|
How weather works
Observing weather
Analysing
weather
Forecasting
Climate & climates
Other useful
information
|
|
Meteorological Data - Overview |
Note that, while this is an excellent overview for anyone keen to get into the arcane world of meteorological data coding, it was written some time ago. Changes in this area are not large or frequent, but they are incremental so some of the details will have changed since this was written. The WMO maintains up-to-date information in two large Manuals on Codes (available online - volume 1 and volume 2). These (currently) total 1,432 pages, so what follows is very much a summary aimed at radio hams, utility monitors and weather enthusiasts.
My thanks to Hugh Stegman, who compressed so much into so little.
0. Why weather reporting codes?
1. Weather bulletin structure
2. Special weather identifiers
3. A few North American military weather frequencies
4. "Old" bulletin type codes
5. WMO heading regional codes
6. Full list of weather codes
7. Weather code FAQ
8. Useful WWW URLs
A1. Full WMO Heading decoder
A2. What BBB codes mean
A3. The METAR code
A4. The SYNOP code
A5. The SVXX/BUOY code
Weather Communications Codes
A Breathless Overview by Hugh Stegman NV6H
Sources are many, but mostly:
World Meteorological Organization http://www.wmo.ch/
National Oceanic and Atmospheric Agency
http://www.nws.noaa.gov/
0. Why Weather Reporting Codes?
===============================
In a word, clarity.
Weather observation codes are very similar from one country to
another, facilitating the exchange of information despite the
Babel of languages, measurement units, and time zones.
Meteorological groups meet regularly to deal with these issues.
The resulting codes are appropriate to the type of information
being exchanged. They also provide well-documented national
practice exceptions such as the use of inches, feet, and miles for
pressure, clouds, and visibility in United States aviation
weather.
In another word, brevity.
When these codes were invented, back in the age of mechanical
teleprinters, 50 WPM wasn't bad and 75 was screaming. There was
no alternative to compact coding systems, if weather wires were to
move a whole world's information in anything approaching a timely
manner. After all, nothing's older than yesterday's weather
forecast.
Extreme brevity is no longer as important in an age of real-
time binary observations being plotted in 3 dimensions on wide-
area networked computer screens, but standardization is.
Standards are currently maintained by the World Meteorological
Organization, a UN body in Geneva with over 150 members. Changes
are periodically agreed on and codified in the canonic WMO
Handbook No. 306, available from the WMO web site. (Be ready to
pay in Swiss francs.)
Most current issues in the text-based communications have to do
with the very gradual changeover from the practices of different
countries into the more standard WMO formats. These changes are
minor. In the US, for example, the two big ones are the switch to
Celsius in reporting airport temperatures and dewpoints, and a
gradual change from one bulletin heading syntax to another.
<top>
1. Weather Bulletin Structure
=============================
Most of the world's thousands of different weather reports use
a standard format. The United States is adopting this, however
slowly, for its 6000+ products.
Here's an example of the kind of thing one will copy on utility
radio stations. Landlines (the "weather wire" aka the "big wire")
and computer servers use very similar structures:
ZCZC
SAUS80 KWBC 011200 RRC
METAR
KDAL 011150Z 00000KT SKC 14/11 A3010 RMK 10170 20133=
[more lines of data]
NNNN
Item One : START SIGNAL
-----------------------
In this example: ZCZC
Some standard starting signal such as a Telex code, ASCII
string, or whatever is used by the particular network.
Item Two: STANDARD INTERNATIONAL HEADER (in WMO format)
-------------------------------------------------------
In this example: SAUS80 KWBC 011200 RRC
The header identifies the type of product, and to whom it
applies.
Syntax:
TTLLii CCCC DDHHMM (BBB),
where TT=Type, LL=Location, ii=Number, CCCC=Collection center ID,
DDHHMM = date/time group of day/hour/minute, and (BBB) is an extra
information string not always used.
These headers contain a great deal of information in their
compact text strings, with many characters pointing into the
infamous "WMO tables" of very highly organized information on just
about every weather possibility anywhere in the world.
There are a number of computer programs, and even web sites,
that allow the decoding of these headers. One drops the header
into a text box and gets back several lines of information. A
useful decoder of this type is at the US National Weather Service
site. The URL is:
http://www.nws.noaa.gov/oso/hdecode.shtml.
Sometimes US bulletins have a slightly different header, either
by itself or next to the WMO format. This is the notorious "AFOS
PIL," formerly the standard wire ID for all US weather product.
AFOS is the Automated Field Operations and Services network
used since 1982, currently being phased out for AWIPS, the
Advanced Weather Interactive Processing System. AFOS uses an
older ID number called the PIL for "Product Inventory Lookup," but
all AWIPS communications will use either the WMO style or both.
Item 3: Text
------------
The content of the bulletin.
In our example:
METAR
KDAL 011150Z 00000KT SKC 14/11 A3010 RMK 10170 20133=
[.]
METAR is a code specifier, indicating that the following lines
of data will be in the METeorological observation, Aviation,
Routine format, as currently set forth in WMO standard code FM 15-
IX, Extended. This is a very common single-line format for hourly
aviation reports. If more timely information needs to be passed
it's done in the similarly structured SPECI (SPECIal weather
change notice, WMO FM-16). There are also standards for TEMPO
(TEMPOrary), and TAF (Terminal Aerodrome Forecast). For example,
FTUS in a header always means a standard set of TAF.
Since METARs use a lot of plain text, it's easy to decode them
in your head. In fact, their expansion into ordinary language
provides much of the ATIS (Automated Terminal Information System)
and VOLMET ("Flying Weather") transmissions we hear. They can
also be automatically stored on web sites that provide weather
information for pilots, and expanded when looked up.
For a start, KDAL is the 4-letter ICAO international airport
identifier (for Love Field, Dallas, TX). The next two groups are
a date/time stamp and a wind direction/speed, followed by a number
of observations that change with type of weather station and
country. Finally there's an optional RMK (ReMarKs) field followed
by the appropriate codes for things like storm activity, dust,
snow, and such. The = at the end of the METAR is a terminator,
corresponding roughly to the old CW BT (short-break) signal.
The key word in METAR is Routine. Significant, non-routine,
weather features that affect aviation will be passed in numbered
warnings called SIGMET, for SIGnificant METeorological. It the
US, these are divided into convective SIGMETs (thunderstorms,
tornadoes) and non-convective SIGMETs (turbulence, icing, etc.).
Along with all these aviation formats, we will also see
surface synoptic observations in their own codes. These will be
designated as AAXX or SYNOP (land synoptic code, WMO FM-12), and
BBXX or SHIP (ship synoptic code, WMO FM-13) Moored weather buoys
can be treated as stationary ships. Drifting ones, or those with
special observations, have a BUOY code (SSVX, WMO FM-18X ,
replaces DRIFTER) for them.
We'll have way more about all these codes.
Item 4: End-Of-Message signal
-----------------------------
A standard ending signal such as the NNNN in our example.
<top>
2. Special Weather Identifiers
==============================
Weather stations use three different types of identifiers. One
is the numeric WMO form that we see in some data fields. These
can be looked up in a list available online or from WMO as a
loose-leaf publication that is updated frequently by subscription.
The list is hundreds of pages long in ASCII text, unfortunately,
so it is not reproduced here.
Another is the radio callsign, which we typically see only for
Volunteer Observation System (VOS) "ships of opportunity," which
have agreed to put certain standard instruments aboard and train
one or more crew members in their proper use. The Beaufort wind
arrows and sky condition reports shown on oceanic weather charts
are usually labeled with these callsigns, as are their synoptic
reports in SHIP code.
Sometimes a hurricane warning or other advisory will also show
the callsign of a VOS ship whose report has been used. These are
the only times, typically, that radio calls appear in a weather
product. WMO maintains a database of those callsigns. A
semicolon-delimited record dump from 1999 is available on their
web site, or a subscription can be purchased for more timely data.
More important for our uses, though, are the 4-letter
identifiers that show in the CCCC field of bulletin headings, or
in the source field of many coded observations. These look like
radio callsigns, but they are international IDs that happen to
mimic the ICAO 4-letter airport convention, and in fact actually
use it in the case of civilian airport METARs. However, many of
these identifiers can also refer to central weather offices,
information collection and relay points, or even automated
instruments in the field.
CONUS airports form the 4-character ICAO ID by prepending K to
the three-letter IATA identifiers we're used to seeing on our
baggage. Alaskan IDs begin with PA, Hawaiian with PH, and Puerto
Rico with TJ.
The actual callsigns of the transmitters subsequently used to
pass information from this system will vary. Many US military
broadcasts are in fact completely unidentified except for the
product sources in the headers, which have nothing to do with who
ultimately broadcasts the information.
US military transmitters are usually at Elkhart, NE, near
Offutt Air Force Base; Saddlebunch Key, near the Key West Naval
Communication Station; Roosevelt Roads, the US Navy base in Puerto
Rico. Schedules change almost weekly, as all remaining US
military HF weather transmissions are by request from the fleet or
the Air Force.
Here are some commonly seen identifiers:
ID Country/Agency Office
---- --------------- ----------------------------------------
AMMC Australia Bureau Of Meteorology, Brisbane
BABJ China Beijing
CWAO Canada Canadian Met. Centre, CN
CWEG Canada Alberta Weather Centre, AB
CYYZ Canada Toronto Weather Centre, ON
EBBR Belgium Brussels
EDZW Germany Met. Communications Office
EGRR UK British Met. Office, Bracknell, GB
EHAM Netherlands Amsterdam
EKMI Denmark Met. Institute
FABL South Africa Bloemfontein
FAJS South Africa Johannesburg
FAPR South Africa Pretoria
KAWN US Air Force Aviation Weather Network, Offutt AFB, NE
KGWC US Air Force Global Weather Center, Offutt AFB, NE
KKCI NWS/NCEP Aviation Weather Center, Kansas City, MO
KMKC NWS/NCEP SIGMET Center, Kansas City, MO
KNGU US Navy US Navy Weather Center, Norfolk, VA
KNHC NOAA/NWS/NCEP National Hurricane Center, Tropical
Prediction Center, FL
KWBC NWS/NCEP NWS Central Operations, MD
KWBx NCEP Output from NWS models, per table below
KWNC NWS/NCEP Climate Prediction Center
KWNO NWS/NCEP Aviation Weather Center, Kansas City, MO
KWNS NWS/NCEP Storm Prediction Center
LEMM Spain Met. Communication Center, Madrid
LFPW Meteo France Met. Center, Toulouse
LIIB Italy Met. Communication Center, Rome
LIMC Italy Milan
LOWM Austria TAF, Surface Observations
MMGL Mexico Guadalajara/Miguel Hidalgo y Costilla
Int'l (See Mexican METAR sources below)
MMMD Mexico Merida/Lic. Manuel Crecencio Rejon Int'l
MMMX Mexico Mexico/Lic. Benito Juarez Int'l
MMMZ Mexico Mazatlan/General Rafael Beulna Int'l
MNMG Nicaragua Managua, Surface Observations
MPTO Panama Tocumen, Surface Observations
MYNN Bahamas Nassau METAR, Bahamas
NZKL New Zealand Metservice Wellington, NZ
NZWN New Zealand Wellington
PAFA NWS/NCEP Fairbanks, AK
PAJN NWS/NCEP Juneau, AK
PANC NWS/NCEP Anchorage, AK
PHNL NWS/NCEP Honolulu, HI
RJAA Japan New Tokyo Airport
RJTD Japan Japanese Met. Agency, Tokyo
RPLL Philippines Aquino International Airport
RUMS Russia Moscow
SABM Argentina Natl. Met. Office, Buenos Aires
SBBR Brazil INMET, Brasilia Airport
TJSJ NWS/NCEP Puerto Rico
TJNR US Navy Roosevelt Roads Naval Station, PR
TTPP Trinadad&Tobago Caribbean METAR
VTBB Thailand Bangkok METAR
YBBN Australia Airport Met. Office, Brisbane
YMMC Australia Met. Centre, Melbourne
In KWBx, (x) can be:
C = NCEP AVN and all other products not listed below
D = Eta/Early Eta
E = ETA/mesoEta
F = Nested Grid Model
G = Rapid Update Cycle
H = Medium Range Forecast Model
I = Sea Surface Temperature Analysis
J = Wind/Wave model
K = ENS/Global Ensemble FCST
L = ENS/Regional Ensemble FCST
M = Ocean Analysis Models
N = Ocean Forecast Models
O = Merge of Models
Z = NCEP "tiles" from models
Mexican METAR sources are as follows:
SAMX41 MMMX
METAR
MMAA - Acapulco/General Juan N. Alvarez Int'l
MMBT - Bahias Dehuatulco
MMCB - Cuernavaca
MMMX - Mexcio/Lic. Benito Juarez Int'l
MMOX - Oaxaca
MMPA - Poza Rica
MMPB - Puebla
MMPS - Puerto Escondido
MMQT - Queretaro
MMTL - Tulancingo
MMTM - Tampico/General Francisco Javier Mina Int'l
MMTO - Toluca/Lic. Adolfo Lopez M.
MMVR - Veracruz/General Heriberto Jara Int'l
MMZH - Zihuatanejo
SAMX42 MMGL
METAR
MMAS - Aguascalientes
MMEP - Tepic
MMGL - Guadalajara/Miguel Hidalgo y Costilla Int'l
MMIA - Colima
MMLO - Del Bajio/Int'l Guanajuato
MMMM - Morelia
MMPN - Uruapan
MMPR - Puerto Vallarta/Lic. Gustavo Dias Ordaz Int'l
MMSP - San Luis Potosi
MMZC - Zactecas
MMZO - Manzanillo Int'l
SAMX43 MMMZ
METAR
MMCL - Culiacan
MMCN - Ciudad Obregon
MMDO - Durango
MMGM - Guaymas/General Jose Maria Yanez Int'l
MMHO - Hermosillo/Int'l
MMLM - Los Mochis
MMLP - La Paz/General Manuel Marquez de Leon Int'l
MMLT - Loreto Int'l
MMML - Mexicali/General Rodolfo Sanchez Taboada Int'l
MMMZ - Mazatlan/General Rafael Beulna Int'l
MMSD - San Jose del Cabo Int'l
MMTJ - Tijuana/General Abelardo L. Rodriguez Int'l
SAMX44 MMMD
METAR
MMCE - Ciudad del Carmen
MMCM - Chetumal Int'l
MMCP - Campeche
MMCZ - Cozumel/Int'l
MMMD - Merida/Lic. Manuel Crecencio Rejon Int'l
MMMT - Minatitlan
MMTG - Tuxtla Gutierrez (mil)
MMTP - Tapachula Int'l
MMUN - Cancun Int'l
MMVA - Villahermosa
SAMX45 MMMY
METAR
MMAN - Monterrey Int/Aeropuerto del Norte
MMCS - Ciudad Juarez/Abraham Gonzales Int'l
MMCU - Chihuahua/Int'l
MMCV - Ciudad Victoria
MMIO - Satillo
MMMA - Matamoros/Int'l
MMMY - Monterrey/General Marianao Escobedo Int'l
MMNL - Nuevo Laredo Int'l
MMRX - Reynosa/Genral Lucio Blanco Int'l
MMTC - Torreon Int'l.
<top>
3. A Few North American Military Weather Frequencies
====================================================
Most frequencies are assigned channel center. The dial/window
frequency for FAX is usually 1.9 kHz lower, as we tune it in USB.
RTTY can vary as much as 2 kHz either way, depending on receiver
and habits of the operator.
RTTY is 850 Hz shift, 75 baud, ITA2 Baudot code. FAX is 120
lines per minute, with an Index Of Cooperation of 576. The US Air
Force transmissions are not necessarily parallel, and not all
frequencies are in use at all times.
This list is far from exhaustive, and frequencies change a
couple of times in the average year. Consult Internet and
published lists for more recent data.
3231.0 KAWN RTTY (Tune in LSB)
3131.0 KGWC FAX (Tune in USB)
4271.4 CFH FAX (Canadian Forces, Halifax; also RTTY)
4855.0 KGWC FAX
6496.4 CFH FAX (Canadian Forces, Halifax; also RTTY)
7398.0 KGWC FAX
7784.0 KAWN RTTY
7870.0 KGWC FAX
10536.0 CFH FAX (Canadian Forces, Halifax; also RTTY)
11120.0 KAWN RTTY (Tune in LSB)
11120.0 KGWC FAX (Tune in USB)
13510.0 CFH FAX (Canadian Forces, Halifax; also RTTY)
13530.0 KAWN RTTY
15781.0 KGWC FAX
19324.5 KAWN RTTY
19363.0 KGWC FAX
19530.0 KAWN RTTY (Usually "fox" marker)
<top>
4. "Old" Bulletin Type Codes
============================
These use the first two letters TT in the group TTLLii at the
beginning of the heading. These provide a quick indication most
of the time, but WMO has subsequently adopted a far more detailed
system which we will see in the appendices to this document.
Syntax: TTLL, where:
TT Explanation
====== ===========
AB Weather summaries
AC Convective outlooks
AS Surface analyses
AU Upper level analyses
AX Tropical discussions
CS Climatic data
CU Upper air climatic data
FA Area forecasts
FB Aviation forecasts
FC Recovery forecasts
FD Winds aloft forecasts
FE Extended forecasts
FK Air stagnation forecasts
FO Model output forecasts
FP Public forecasts
FQ Metropolitan forecasts
FS Surface forecasts
FT Terminal forecasts
FU Upper level forecasts
FV Avalanche forecasts
FW Recreational forecasts
FX Prog discussions
FZ Marine forecasts
NF Special notices
NO General notices
RW River conditions, flood info and forecasts
SA Surface observations
SD Radar observations
SE Earthquake observations
SF Sferics weather data
SH Synoptic ship reports
SI Intermediate synoptic reports
SM Synoptic observations
SP Special reports
SR River and rainfall observations
SS Ship reports
ST Ice reports
SX Miscellaneous observations
TB Satellite data
UA Pilot reports
UC,UE,UF Upper air data from ships
UG,UH,UI Pibal/Rawinsonde data
UJ,UK,UM Radiosonde data
UN,UQ Radiosonde data
UP Pibal/Rawinsonde data
UR Aircraft reconnaissance data
US,UW,UX Radiosonde data
UT Aircraft reports
UY,UZ Upper air data
WF Tornado warnings
WO Tropical depression advisories
WR Flash flood warnings
WS Sigmets
WT Tropical storm/hurricane advisories
WU Severe thunderstorm warnings
WW Special weather statements and weather watches
<top>
5. WMO Heading Regional Codes
These are used in most bulletin headings in the LL or AA part
of the TTLLii / TTAAii group.
LL Region
== ======
AB Albania
AG Argentina
AH Afghanistan
AI Ascension Island
AJ Azerbaijan, Republic of
AK Alaska
AL Algeria
AN Angola
AT Antigua, St. Kitts & British islands in the vicinity
AU Australia
AY Armenia. Republic of
AZ Azores Islands
BA Bahamas
BC Botswana
BD Brunei Darussalam
BE Bermuda
BG Bosnia & Herzegovina
BH Belize
BI Burundi
BJ Benin
BK Banks Islands
BM Myanmar (Burma)
BN Bahrain
BO Bolivia
BR Barbados
BU Bulgaria
BV Bouvet Island
BW Bangladesh
BX Belgium, Luxembourg
BY Belarus, Republic of
BZ Brazil
CD Chad
CE Central African Rep
CG Congo
CH Chile
CI China
CM Cameroon
CN Canada
CR Canary Islands (Spain)
CS Costa Rica
CT Canton Island
CU Cuba
CV Cape Verde Islands
CY Cyprus
CZ Czech Republic
DJ Djibouti
DL Germany
DN Denmark
DO Dominica
DR Dominican Republic
DY Democratic Yemen
EG Egypt
EO Estonia
EQ Ecuador
ER United Arab Emirates
ES El Salvador
ET Ethiopia
FA Faeroes Islands
FG French Guyana
FI Finland
FJ Fiji Islands
FK Falkland Isl. (Malvinas)
FP Saint Pierre Island & Miquelon
FR France
FW Wallis and Futuna Isl.
GB Gambia
GC Cayman Islands
GD Grenada
GE Gough Island
GG Georgia, Republic of
GH Ghana
GI Gibraltar
GL Greenland
GM Guam Island
GN Guinea
GO Gabon
GQ Equatorial Guinea
GR Greece
GU Guatemala
GW Guinea-Bissau
GY Guyana
HA Haiti
HE St. Helena Island
HK Hong Kong
HO Honduras
HU Hungary
HV Burkina Faso
HW Hawaiian Islands
IC Comoros
ID Indonesia
IE Ireland
IL Iceland
IN India
IQ Iraq
IR Iran
IS Israel
IV Cote d'Lvoire
IY Italy
JD Jordan
JM Jamaica
JP Japan
KA Caroline Islands
KB Kiribati
KG Kirgiristan, Republic of
KI Christmas Islands
KK Cocos Islands
KN Kenya
KO Korea, Republic of
KP Cambodia
KR Democratic People's Republic of Korea
KU Cook Island
KW Kuwait
KY Kyrghyzstan, Republic of
KZ Kazakhstan,Republic of
LA Lao People's Democratic Rep
LB Lebanon
LC Saint Lucia
LI Liberia
LJ Slovenia
LN Southern Line Islands
LS Lesotho
LT Lithuania
LV Latvia
LY Libyan Arab Jamahiriya
MA Mauritius
MB Marion Island
MC Morocco
MD Madeira Island
MF Saint-Martin, Saint-Bartholomew, Guadeloupe, etc
MG Madagascar
MH Marshall Islands
MI Mali
MJ Former Yugoslav Rep. of Macedonia
ML Malta
MN St.Maarten, St.Eustatius & Saba
MO Mongolia
MR Martinique Island
MS Malaysia
MT Mauritania
MU Macao
MV Maldives Islands
MW Malawi
MX Mexico
MY Mariana Islands
MZ Mozambique
NC New Caledonia Island
NG Papua New Guinea
NI Nigeria
NK Nicaragua
NL Netherlands
NM Namibia
NO Norway
NP Nepal
NR Niger
NU Netherlands Antilles (Aruba, Bonaire, Curacao)
NV Vanuatu
NW Nauru Island
NZ New Zealand
OM Oman
OR South Orkney Islands
OS Austria
PF French Polynesia Islands
PH Philippines
PI Phoenix Islands
PK Pakistan
PL Poland
PM Panama
PO Portugal
PR Peru
PT Pitcairn Island
PU Puerto Rico
PY Paraguay
QT Qatar
RA Russia, Republic of (East)
RE Reunion and assoc. islands
RH Croatia
RM Republic of Moldova
RO Romania
RS Russia, Republic of (West)
RW Rwanda
SB Sri Lanka
SC Seychelles Islands
SD Saudi Arabia
SG Senegal
SI Somalia
SK Sarawak
SL Sierra Leone
SM Suriname
SN Sweden
SO Solomon Islands
SP Spain
SQ Slovakia
SR Singapore
SU Sudan
SV Swaziland
SW Switzerland
SX Santa Cruz Island
SY Syria
SZ Spitzbergen Islands
TC Tristan da Cunha
TD Trinidad and Tobago
TG Togo
TH Thailand
TI Turks and Caicos Islands
TK Tokelau Islands
TM Timor
TN Tanzania, United Rep of
TO Tonga
TP Sao Tome and Principe
TR Turkmenistan, Republic of
TS Tunisia
TU Turkey
TV Tuvalu
TZ Tajikistan, Republic of
UG Uganda
UK United Kingdom of Great Britain and Northern Ireland
UR Ukraine, Republic of
US United States of America
UY Uruguay
UZ Uzbekistan, Republic of
VG St. Vincent and the Grenadines
VI Virgin Islands
VN Venezuela
VS Vietnam
YE Yemen
YG Yugoslavia
ZA South Africa
ZB Zambia
ZM Western Samoa
ZR Zaire
ZS American Samoa
ZW Zimbabwe
<top>
6. Full List Of Weather Codes
=============================
Text-Based Codes
----------------
Text-based codes pass data as letters and numbers
(alphanumerics), as opposed to a continuous bit stream. They are
usually broken up into standard groups for readability.
Baudot (ITA2), SITOR, and ASCII (ITA 5) are examples of text-
based transmission modes. These codes are usually substitutions
into lookup tables of longer strings or amounts, though
occasionally raw data is transmitted this way, as numbers or
encoded into alphanumerics that represent the appropriate binary
bits for direct crunching by computers.
SYNOP (WMO FM-12) Surface Synoptic Reports
SHIP (WMO FM-13) Ship Synoptic Reports
Both of the above use a ship callsign or a
WMO sea or land station number, followed by a
time stamp. Up to four more sections follow,
in 5 number groups except for the word ICE + a
short text string, if ice observations are
being passed in that section of the synopsis.
METAR (WMO FM-15) Aviation Routine Observations
Hourly reports, usually at airports.
SPECI (WMO FM-16) Special Aviation Weather Change
For important changes before the next scheduled
METAR. Expands to word "SPECIAL" in voice ATIS
or VOLMET, both of which use an altered METAR
format.
DRIFTER (WMO FM-18IX) Drifting Buoy Obs, now BUOY
BUOY (WMO FM-18X) Buoy Observations
Weather buoys can be treated as ships and
pass data in SHIP code, or use this special
format labeled SVXX in bulletins.
RADOB (WMO FM-20) Radar Observations
RADREP (WMO FM-22) Radiological Data
PILOT (WMO FM 32) Upper Level Wind
PILOT SHIP (WMO FM 33) Upper Level Wind
PILOT MOBIL (WMO FM 34) Upper Level Wind
TEMP (WMO FM-35) Upper Level Observations
TEMP SHIP (WMO FM-36) Upper Level Observations
TEMP DROP (WMO FM-37) Aircraft Dropsonde Obs.
TEMP MOBIL (WMO FM-38) Upper Level Observations
ROCOB (WMO FM-39) Rocketsonde Reports
ROCOB SHIP (WMO FM-40) Rocketsonde Reports
CODAR (WMO FM-41) Aircraft Report
AMDAR (WMO FM-42) Aircraft Report
ICEAN (WMO FM-44) Ice report
IAC (WMO FM-45) Ship surface observation
IAC FLEET (WMO FM-46) Ship surface observation
GRID (FM 47-IX Ext) Gridded Data (sent as text)
GRID provides observation data and information
on how to plot it. The result is a picture.
WINTEM (WMO FM-50) Upper-level Winds, Temperatures
TAF (WMO FM-51) Terminal Aerodrome Forecasts
A series of standard groups for valid times,
starting FM "(in voice, "from") for the first,
then with BCMG (in voice, "becoming,"). If
weather is expected to change before the first
valid time, a TEMPO ("temporarily") group is
included. TAF, when expanded into plain speech,
is part of the VOLMET.
ARFOR (WMO FM-53) Aviation Routine Forecasts
ROFOR (WMO FM-54) On-Route Aviation Forecasts
RADOF (WMO FM-57) Radiological Dose Predictions
MAFOR (WMO FM-61) Shipping Area Forecasts
TRACKOB (WMO FM-62) Oceanographic Data
BATHY (WMO FM-63) Oceanographic Data
TESAC (WMO FM-64) Oceanographic Data
WAVEOB (WMO FM-65) Oceanographic Data
HYDRA (WMO FM-67) Hydrological River Reports
HYFOR (WMO FM-68) Hydrological Forecast
CLIMAT (WMO FM-71) Surface climatic data
CLIMAT SHIP (WMO FM-72) Surface marine climatic data
NACLI, CLINP,
SPCLI, CLISA,
INCLI (WMO FM-73) Oceanic climatic data
CLIMAT TEMP (WMO FM-75) Upper-air climatic data
CLIMAT TEMP SHIP (WMO FM-76) Upper-air marine climatic data
SFAZI (WMO FM-81) Special Atmospheric Reports
SFLOC (WMO FM-82) Special Atmospheric Reports
SAREP (WMO FM-85) Satellite Cloud Interpretations
SATEM (WMO FM-86) Satellite Remote Upper Soundings
SARAD (WMO FM-87) Satellite Radiance Observations
SATOB (WMO FM-88) Satellite Temps & Radiance Balance
CREX (None A.P.) Coded raw data table driven obs.
AIRMET Aviation Weather Advisory
Like a SIGMET, in a special clipped text format,
but for less serious weather features.
AIREP ICAO Air Report, like a PIREP
PIREP Pilot Report of standard items
PIREPs go into a database, to be used by weather
offices when briefing pilots.
RECCO Aircraft Reconnaissance Report
One important use of the RECCO format is for
data returned by hurricane aircraft every 30
minutes.
TEMPO Rapidly Changing Weather
TEMPO is usually part of a TAF, describing
weather expected to change within the hour.
SIGMET SIGnificant METeorological warning
A weather feature that poses a hazard to
aviation. In the US, divided into convective
(severe thunderstorms or tornadoes), and non-
convective (things like turbulence and icing).
Interestingly, SIGMET is also an officially
defined hypertext markup document type.
SIGMETs are in a clipped text format.
VORTEX Aircraft Hurricane Observations
Data passed from dropsonde aircraft while on
the actual pass through the hurricane, including
position fix, pressure, wind, and eye structure.
Binary Codes
-----------
BUFR (WMO FM-94) Binary Universal Form for the
Representation of met. data
BUFR is a completely binary code for computer
crunching, passing data in octets as a binary
stream, beginning with the designator BUFR in
CCITT ITA5)
GRIB (FM 92-IX Ext) Gridded Binary Data
GRIB provides observation data and information
on how to plot it, but unlike GRIB the data is
intended for computer crunching alone. It, too
is passed as octets, but in a text form these
can show as hexadecimal bytes 00 through FF.
The result looks like a "hex dump" with numbers
and letters A through F.
<top>
7. Weather Code FAQ
===================
Here are some common questions seen on Internet, and in mail to
Utility World:
1. Q. I found an unid RTTY transmission that looks like "numbers,"
but the format is weird and some groups have letters.
A. Look for things we've talked about, like AAXX, BBXX, METAR,
SPECI, TEMPO, or KAWN, and you might be surprised.
2. Q. I went to the Air Force frequencies you wrote about, but
nothing happened.
A. Since all US HF military weather is on request, the
schedules and frequencies are nearly as changeable as, well, the
weather.
3. Q. I found the US Air Force FAX you talk about, and I seem to
be in sync, but all I get is a skinny white line.
A. A lot of these faxes are apparently some sort of raster
grid, and if there's no significant weather to plot, all that
comes out on the amateur's typical computer screen is the sync
beep at the edge. When there is significant weather, it can
show up as standard synoptic symbols such as the two lines and a
jagged arrow meaning "thunderstorm," or as a number, presumably
for a SIGMET or similar.
Everything else is black, except for a few groups looking like
WMO headers, and maybe a couple of chicken scratchings that are there
just because the equipment does these things.
This is a good reason not to leave the printer on for Air Force
weather fax.
4. Q. I'm getting good copy of the RTTY, but it's all numbers and
doesn't fit any of these codes.
A. Yes, you've noticed this too. My guess is that it's raw
output in some military version of something like GRID, GRIB, or
BUFR.
5. Q. So where is the KAWN transmitter anyway?
A. It's wherever the US Air Force Automated Weather Network,
formerly the Aviation Weather Network, is being picked up and
relayed onto the radio. Since KAWN is not a radio callsign, it
contains no information as to transmitter locations. The same
holds for KGWC, KNHC, etc..
6. Q. What is QNH?
A. Altimeter setting in international and/or Metric units.
Below a certain altitude, pilots manually offset their altimeters
to compensate for changing barometric pressures which would
otherwise cause measurement errors. It comes from an old
international procedural "Q" signal from the days of Morse code.
Simplified meaning of the old prosign is:
QNH? = "What is your station's altimeter setting (usually in
Hectopascals) [at -?]," and
QNH = "Set your altimeter to - [at - hours]."
In the US national practice, "Altimeter" is substituted for
"QNH," and the unit is inches of mercury. This is one way to tell
whether a voice bulletin is coming from the US or somewhere else.
<top>
8. Useful WWW URLs
==================
BUFR Code Specifications:
http://www-dd.fsl.noaa.gov/bufrFormat.html
Details of "Hurricane Hunter" use of RECCO and VORTEX codes:
http://www.hurricanehunters.com/
Entry point into weather station designator database:
http://www.nws.noaa.gov/oso/oso1/oso12/siteid.htm
NCDC Weather Station Locator:
http://www.ncdc.noaa.gov/ol/climate/stationlocator.html
SHIP synoptic code, with US Navy extensions
http://waves.ncdc.noaa.gov/ship/sec1-ch1.htm
Terminal Aerodrome Forecast code:
http://www.nws.noaa.gov/oso/oso1/oso12/d31/D31links.htm
UK Meteorological Office:
http://www.met-office.gov.uk/index.html
US Federal Meteorological Handbook:
http://www.nws.noaa.gov/oso/oso1/oso12/fmh1.htm
WMO Technical Library:
http://www.wmo.ch/web/arep/lib1/index.html
Appendices to this document
===========================
1. Full WMO Heading Decoder
2. Guide to the (BBB) Codes
3. The METAR Code
4. The SYNOP Code
5. The SVXX/BUOY Code
<top>
Appendix #1: Full WMO Heading Decoder, With Tables
==================================================
The FULL symbolic form of the WMO abbreviated heading is:
T1T2A1A2ii CCCC YYGGgg (BBB)
The full lookup format for the WMO Abbreviated Heading uses a
format where the first character of the "Type" field (T1) becomes
the key to what the subsequent characters mean, and then some of
these can also affect what happens next. This is how a 6-
character group can store so much information.
The key list of T1 values is Table A from WMO Manual 306,
(Code) or Observing / Product Type. It's best visualized as a
matrix of jumps to subsequent tables, so that's just what we'll
do. Get the first letter T1 from your bulletin, then look across
to determine how to interpret subsequent characters, then drop
down to the appropriate table and find them.
If this whole thing looks like a potentially good use for
hypermedia like HTML code, well, it's been done. Try the US
web site at http://www.nws.noaa.gov/
TABLE A
Data Type Designator T1 Matrix Table
for
T2A1A2ii definitions
T1 Data type T2 A1 A2 ii Priority Max Lgth
A Analyses B1 C1 C1 ** 3 3800
B Service message *** *** *** *** 1/2/4* 3800
C Climatic data B1 C1 C1 ** 4 3800
D Grid point
information (GRID) B2 C3 C4 D2 3 3800
E Satellite imagery B5 C1 C1 ** 3 (1)
F Forecast B1 C1 C1 ** 3 3800
G Grid point
information (GRID) B2 C3 C4 D2 3 3800
H Grid point
information (GRIB) B2 C3 C4 D2 3 15,000
I Binary observation
- BUFR B3 C6 C3 ** 3 15,000
J Binary forecast
- BUFR B3 C6 C3 ** 3 15,000
K CREX C7 C7 C3 ** 2 3800
L --
M --
N Notices B1 C1 C1 ** 4 3800
O Oceanographic (GRIB) B4 C3 C4 D1 3 15,000
P Pictorial
information(binary) B2 C3 C4 D2 3 15,000
Q Pictorial
information regional B2 C3 C5 D2 3 (1)
R --
S Surface data B1 C1/C2 C1/C2 ** 2/4* 3800
T Satellite data B1 C3 C4 ** 2 3800
U Upper-air data B1 C1/C2 C1/C2 ** 2 3800
V National data (3) C1 C1 ** (2) (1)
W Warnings B1 C1 C1 ** 1 3800
X GRID regional use B2 C3 (2) D2 3 3800
Y GRIB regional use B2 C3 (3) D2 3 15,000
Z GRIB National use (3) (3) (3) (3) 3 15,000
* Priority level:
1 is allocated to service messages
2 is allocated to data and request messages
4 is allocated to seismologic data (T1T2 = SE) or administrative
messages
** See Para.2.3.2.2 (of WMO manual) for definition and use
*** See Para.2.4.2.3 for definition and use
(1) Size to be defined at a later date
(2) To be determined later date
(3) Table B2 or national table
DATA TYPES Y and Z uses National tables in some countries
This then selects one of the following:
Table B1 - Data Type Designator
Table B2 - Data Type Designator
Table B3 - Data Type designator
Table B4 - Data Type Designator
Table B5 - Data Type Designator
Table C1 - Geographical Designator
Table C2 - Geographical Designator (ships & Ocean)
Table C3 - Geographical Designator
Table C4 - Reference Time Designator
Table C5 - Reference Time Designator
Table C6 - Data Type Designator
Table C7 - Geographical Designator
Table D1 - Level Designator (ocean)
Table D2 - Level Designator
and
U.S. National Tables
Table B6 - Data Type Designator
Table C8 - Geographical Area Designator (including WMC
Washington GRID Numbers)
Table C9 - Geographical Area (Tiles) used with KWBx when x = Z
Table C10 - Reference Time Designator
Table D3 - Level Designator ii
T1 is taken from WMO Manual 386 table A. It is an alpha
character that designates the general code form of the contents of
the bulletin (Coded or plain text).
T2 is taken from WMO Manual 386 tables B1 through B6 depending
on the designator T1 in table A. It is an alpha character that
designates the data type.
A1 is taken from WMO Manual 386 tables C1 through C6 depending
on designator T1 in table A ( U.S. National practice through C9 ).
It is an alpha character that designates the geographical area the
content of the bulletin covers.
A2 is taken from WMO Manual 386 tables C1 through C5 depending
on designator T1 in table A ( U.S. National practice through C9 ).
It is an alpha character that designates the geographical area, or
may define the forecast period.
ii is taken from the WMO Manual 386 paragraph 2.3.2.2
definition, or from table D1 or D2 depending on designator T1 in
table A ( U.S. National practice table D3 replaces D2 ). It is a
numeric set of two characters. Go to the WMO message structure for
more details on this group.
When the group ii is used as a US designator, which it is not
always the case, it expands to:
ii = 40, 50, ... 80 Issued from U.S. Pacific WFO
41, 51, ... 81 Issued from Northeast U.S. WFO or RFC
42, 52, ... 82 Issued from southeast U.S. WFO or RFC
(Includes San Juan, PR)
43, 53, ... 83 Issued from North Central U.S. WFO or RFC
44, 54, ... 84 Issued from South Central U.S. WFO or RFC
45, 55, ... 85 Issued from U.S. Rocky Mountains WFO or RFC
46, 56, ... 86 Issued from West Coast WFO or RFC
47, 57, ... 87 Issued from SE Alaska WFO (Juneau, AK)
48, 58, ... 88 Issued from Central Alaska WFO or RFC
(Anchorage, AK)
49, 59, ... 89 Issued from NE Alaska WFO (Fairbanks, AK).
CCCC is the 4-character international code.
YYGGgg is the standard date/time stamp of day, hours, minutes.
(BBB) is an optional group of alpha characters, reference BBB
Group explanation in the next appendix to this document.
Here are the tables for the first group -
T1T2A1A2ii:
Table A
T1:
A Analyses
B Service message
C Climatic data
D Grid point information (GRID)
E Satellite imagery
F Forecast
G Grid point information (GRID)
H Grid point information (GRIB)
I Binary observation - BUFR
J Binary forecast - BUFR
K CREX
L --
M --
N Notices
O Oceanographic (GRIB)
P Pictorial information(binary)
Q Pictorial information regional
R --
S Surface data
T Satellite data
U Upper-air data
V National data
W Warnings
X GRID regional use
Y GRIB regional use
Z GRIB National use
---------------------------------------------------------------
Table B1
T2 (T1 = A, C, F, N, S, T, U or W)
T1 = A Analyses
C Cyclone [TEXT]
G Hydro/Marine [TEXT]
H Thickness [TEXT]
I Ice FM 44 (ICEAN)
O Ozone layer [TEXT]
R Radar [TEXT]
S Surface FM 45 (IAC)/FM 46 (IAC FLEET)
U Upper air FM 45 (IAC)
W Weather Summary [TEXT]
X Miscellaneous [TEXT]
T2 (T1 = C Climatic data):
A Climatic anomalies [TEXT]
E Monthly means (upper air) FM 76 (CLIMAT TEMP SHIP)
H Monthly means (surface) FM 72 (CLIMAT SHIP)
Monthly means (ocean areas) FM 73 (NACLI, CLINP,
SPCLI, CLISA, INCLI)
S Monthly means (surface) FM 71 (CLIMAT)
U Monthly means (upper air) FM 75 (CLIMAT TEMP)
T2 (T1 = F Forecasts)
A Aviation area /GAMET/advisories FM 53 (ARFOR)/[TEXT]
B Upper winds and temperatures FM 50 (WINTEM)
C Aerodrome (VT > 12 hours) FM 51 (TAF)
D Radiological trajectory dose FM 57 (RADOF)
E Extended [TEXT]
F Shipping FM 46 (IAC FLEET)
G Hydrological FM 68 (HYFOR)
H Upper air thickness [TEXT]
I Iceberg [TEXT]
J Radio warning service (incl IUWDS data) [TEXT]
K Tropical cyclone advisories [TEXT]
L Local/Area [TEXT]
M Temperature extremes [TEXT]
O Guidance [TEXT]
P Public [TEXT]
Q Other shipping [TEXT]
R Aviation route FM 54 (ROFOR)
S Surface FM 45 (IAC)/FM46 (IAC FLEET)
T Aerodrome (VT > 12 hours) FM 51 (TAF)
U Upper air FM 45 (IAC)
V Volcanic ash advisories [TEXT]
W Winter sports [TEXT]
X Miscellaneous [TEXT]
Z Shipping area FM 61 (MAFOR)
T2 (T1=N Notices)
G Hydrological [TEXT]
H Marine [TEXT]
N Nuclear emergency response [TEXT]
O METNO/WIFMA [TEXT]
P Product generation delay [TEXT]
T TEST MSG[System related] [TEXT]
W Warning related and/or cancellation [TEXT]
T2 (T1=S Surface Data)
A Aviation routine reports FM 15 (METAR)
B Radar reports (part A) FM 20 (RADOB)
C Radar reports (part B) FM 20 (RADOB)
D Radar reports (parts A & B) FM 20 (RADOB)
E Seismic data (SEISMIC)
F Atmospherics reports FM 81 (SFAZI)/
FM 82 (SFLOC)/
FM 83 (SFAZU)
G Radiological data report FM 22 (RADREP)
I Intermediate synoptic hour FM 12 (SYNOP)/
FM 13 (SHIP)
L Table driven coded reports FM ?? (CREX)
M Main synoptic hour FM 12 (SYNOP)/
FM 13 (SHIP)
N Non-standard synoptic hour FM 12 (SYNOP)/
FM 13 (SHIP)
O Oceanographic data FM 63 (BATHY)/
FM 64 (TESAC)/
FM 65 (WAVEOB)
FM 62 (TRACKOB)
P Special aviation weather reports FM 16 (SPECI)
R Hydrological (river) reports FM 67 (HYDRA)
S Drifting buoy reports FM 18 (DRIFTER)
T Sea Ice [TEXT]
U Snow depth [TEXT]
V Lake ice [TEXT]
X Miscellaneous [TEXT]
T2 (T1=T Satellite Data)
B Satellite orbit parameters [TEXT]
C Satellite cloud interpretations FM 85 (SAREP)
H Satellite remote upper-air soundings FM 86 (SATEM)
R Clear radiance obs FM 87 (SARAD)
T Sea surface temperatures FM 88 (SATOB)
W Winds & cloud temperatures FM 88 (SATOB)
X Miscellaneous [TEXT]
Y Radiance Balance TM 88 (SATOB)
T2 (T1=U Upper Air Data)
A Aircraft reports FM 41(CODAR), ICAO (AIREP)
D Aircraft reports FM 42(AMDAR)
E Upper-level pressure, FM 35(TEMP)/
FM 36 (TEMP SHIP) temperature, humidity and wind
(Part D) FM 38(TEMP MOBIL)
F Upper-level pressure, temperature, FM 35(TEMP)/
FM 36 (TEMP SHIP)/ FM 38 (TEMP MOBIL)humidity and wind
(Parts C and D) [National and bilateral option]
G Upper-wind (Part B) FM 32(PILOT)/
FM 33 (PILOT SHIP)/
FM 34 (PILOT MOBIL)
H Upper-wind (Part C) FM 32 (PILOT)/
FM 33 (PILOT SHIP)/
FM 34 (PILOT MOBIL)
I Upper-wind (Parts A and B) FM 32 (PILOT)/
FM 33 (PILOT SHIP)/
FM 34 (PILOT MOBIL)
[National and bilateral option]
K Upper-level pressure, temperature, FM 35(TEMP)/FM 36
(TEMP SHIP)/FM 38 (TEMP MOBIL) humidity and wind
(Part B)
L Upper-level pressure, temperature, FM 35
(TEMP)/FM 36 (TEMP SHIP)/FM 38 (TEMP MOBIL)
humidity and wind (Part C)
M Upper-level pressure, temperature, FM 35
(TEMP)/FM 36 (TEMP SHIP)/FM 38 (TEMP MOBIL)
humidity and wind (Parts A and B)
[National and bilateral option]
N Rocketsonde reports FM 39 (ROCOB)/
FM 40 (ROCOB SHIP)
P Upper-wind (Part A) FM 32 (PILOT)/
FM 33 (PILOT SHIP)/
FM 34 (PILOT MOBIL)
Q Upper-wind (Part D) FM 32 (PILOT)/
FM 33 (PILOT SHIP)/
FM 34 (PILOT MOBIL)
R Aircraft report [NATIONAL*] (RECCO)
S Upper-level pressure, temperature, FM 35
(TEMP)/FM 36 (TEMP SHIP) humidity and wind (Part A)
FM 38 (TEMP MOBIL)
T Aircraft report FM 41 (CODAR)
X Miscellaneous TEXT]
Y Upper-wind (Parts C and D) FM 32 (PILOT)/
FM 33 (PILOT SHIP)/
FM 34 (PILOT MOBIL)
[National and bilateral option]
Z Upper-level pressure, temperature, FM 37(TEMP DROP),
humidity and wind from a sonde released by carrier
balloon or aircraft (Parts A, B, C, D)
T2 (T1=W Warnings)
A Airmet [TEXT]
C Tropical cyclone (SIGMET) [TEXT]
E Tsunami [TEXT]
F Tornado [TEXT]
G Hydrological/River Flood [TEXT]
H Marine/Coastal Flood [TEXT]
O Other [TEXT]
S SIGMET [TEXT]
T Tropical cyclone (Typhoon/Hurricane) [TEXT]
U Severe Thunderstorm [TEXT]
V Volcanic Ash Clouds (SIGMET) [TEXT]
W Warnings & weather summary [TEXT]
-----------------------------------------------------------------
Table B2
T2 (T1 = D, G, H, P, Q, V, X or Y)
A Radar data
B Cloud
C Clear air turbulence
D Thickness (relative topography)
E Precipitation
F Aerological diagrams (Ash cloud)
G Significant weather
H Height
I Ice flow
J
K Swell height + combinations
L Plain language
M For national use
N Radiation
O Vertical velocity
P Pressure
Q Wet bulb potential temperature
R Relative humidity
S Snow cover
T Temperature
U Eastward wind component
V
X Lifted index
Y Observational plotted chart
Z Not assigned
------------------------------------------------------------------
Table B3
T2 (T1=I or J Binary Data - BUFR)
S Surface/sea level
U Upper AirOceanographic/limnographic (water properties)
P Pictorial
T Text (plain language information)
X Other data types
Z Mixed data types
------------------------------------------------------------------
Table B4
T2 (T1=O Oceanographic - GRIB)
D Depth
E Ice concentration
F Ice thickness
G Ice drift
H Ice growth
I Ice convergence/divergence
Q Temperature anomaly
R Depth anomaly
S Salinity
T Temperature
U Current component
V not assigned
W Temperature warming
X Mixed data values
------------------------------------------------------------------
Table B5
T2 (T1 = E Satellite Imagery)
C Cloud top temperature
F Fog
I Infrared Range
S Surface temperature
V Visible Range
W Water vapor
Y User specified
Z Unspecified
------------------------------------------------------------------
Table C1
Land observation locations A1A2 use the same country codes as seen
previously for the identical LL in part 5 of our main document.
Please refer to that section.
Other Geographical Area Designators:
AA Antarctic MP Central Mediterranean
AC Arctic MQ Western Mediterranean
AE South-East Asia
AF Africa NA North America
AM Central Africa NT North Atlantic area
AO West Africa
AP Southern Africa OC Oceana
AS Asia OH Sea of Okhotsk
AW Near East
AX Arabian Sea area PA Pacific area
PE Persian area
BQ Baltic Sea area PN North Pacific area
PQ Western North Pacific
CA Caribbean & Central America PS South Pacific area
PW Western Pacific area
EA East Africa PZ Eastern Pacific area
EC East China Sea area
EE Eastern Europe SA South America
EM Middle Europe SE Southern Ocean area
EN Northern Europe SJ Sea of Japan area
EU Europe SS South China Sea area
EW Western Europe ST South Atlantic area
FE Far East XE Eastern hemisphere
XN Northern hemisphere
GA Gulf of Alaska area XS Southern hemisphere
GX Gulf of Mexico area XT Tropical belt
XW Western hemisphere
IO Indian Ocean area XX For use when others
are not appropriate
ME Eastern Mediterranean area
MM Mediterranean area
----------------------------------------------------------------
Table C2
Geographical Designator A1 A2
1. The first letter A1 will denote the nature of the ship or
automatic marine station:
For ocean weather stations: W
For mobile ships and other marine stations: V
2. The second letter A2 will denote the area from which the
reports contained in the bulletin originate:
Designator Data Area
A Area between 30o N - 60o S, 035o W - 070o E
B Area between 90o N - 05o N, 070o E - 180o E
C Area between 05o N - 60o S, 120o W - 035o W
D Area between 90o N - 05o N, 180o W - 035o W
E Area between 05o N - 60o S, 070o E - 120o W
F Area between 90o N - 30o N, 035o W - 070o E
J Area between 60o S
X More than one area
-----------------------------------------------------------------
Table C3
Location Codes
(A1 when T1=D,G,O,P,or T, A2 when T1= I, J, or K
A 0 - 90 W northern hemisphere
B 90W - 180 northern hemisphere
C 180 - 90E northern hemisphere
D 90E - 0 northern hemisphere
E 0 - 90W tropical belt
F 90W - 180 tropical belt
G 180 - 90E tropical belt
H 90E - 0 tropical belt
I 0 - 90W southern hemisphere
J 90W - 180 southern hemisphere
K 180 - 90E southern hemisphere
L 90E - 0 southern hemisphere
N Northern hemisphere
P Area between 64.69N - 136.76W, 55.61N - 13.43W
64.69N - 156.76W, 55.61N - 33.43W
S Southern hemisphere
T 45W - 180 northern hemisphere
U Area between 21.0N - 128.1W, 36.0N - 130.9W
21.1N - 113.0W, 36.2N - 110.5W
V Area between 30.3N - 83.7W, 51.0N - 68.9W
19.8N - 64.5W, 33.3N - 47.1W
X Global Area (area not definable)
When T1=H:
A 0 - 180 E northern hemisphere [21]
B 180 W - 0 northern hemisphere [22]
C 0 - 180 E southern hemisphere [23]
D 180 W - 0 southern hemisphere [24]
E 0 - 355 E northern hemisphere [25]
F 0 - 355 E southern hemisphere [26]
G Regional use
H Not Assigned
I 30 W - 60 E northern hemisphere [37]
J 60 W - 150 E northern hemisphere [38]
K 150 E - 120 W northern hemisphere [39]
L 120 W - 30 W northern hemisphere [40]
M 30 W - 60 E southern hemisphere [41]
N 60 W - 150 E southern hemisphere [42]
O 150 E - 120 W southern hemisphere [43]
P 120 W - 30 W southern hemisphere [44]
Q-S Not Assigned
T 0 - 180 E northern hemisphere [61]
U 180 W - 0 northern hemisphere [62]
V 0 - 180 E southern hemisphere [63]
W 180 W - 0 southern hemisphere [64]
X Regional use
Y-Z Not Assigned
----------------------------------------------------------------
Table C4
Time Designators
A2 when T1 = D,G,H,O, P, or T
A Analysis (00 hour)
B 6 hours forecast
C 12 hours forecast
D 18 hours forecast
E 24 hours forecast
F 30 hours forecast
G 36 hours forecast
H 42 hours forecast
I 48 hours forecast
J 60 hours forecast
K 72 hours forecast
L 84 hours forecast
M 96 hours forecast
N 108 hours forecast
O 120 hours forecast
P 132 hours forecast
Q 144 hours forecast
R 156 hours forecast
S 168 hours forecast
T 10 days forecast
U 15 days forecast
V 30 days forecast
W...Z Not assigned
------------------------------------------------------------------
Table C5
Reference Time Designators
(A2 when T1 = Q, X, or Y)
A Analysis (00 hour)
B 3 hours forecast
C 6 hours forecast
D 9 hours forecast
E 12 hours forecast
F 15 hours forecast
G 18 hours forecast
H 21 hours forecast
I 24 hours forecast
J 27 hours forecast
K 30 hours forecast
L 33 hours forecast
M 36 hours forecast
N 39 hours forecast
O 42 hours forecast
P 45 hours forecast
Q 48 hours forecast
R 54 hours forecast [48+6]
S 66 hours [+12]
T 78 hours
U 90 hours
V 102 hours
W 114 hours
X 126 hours
Y 138 hours
Z 150 hours
------------------------------------------------------------------
Table C6
Data Type Designator
(A1 = I, or J)
1. The designators specified in this table should be used to the
greatest extent possible to indicate the type of data contained
within the body of the BUFR bulletin.
2. Where more than one data type is contained in the bulletin, the
designators for only one of the data types should be used.
3. When the table does not contain a suitable designator for the
data type, an alphabetic designator which is not assigned in the
table should be introduced and the WMO Secretariat notified.
T1 = I Observational Data
and
T2 = S Surface
Designator Data type
A Land based hourly reports
C Climatic reports
I Land intermediate synoptic reports
M Land based Main synoptic reports
N Land based asynoptic intermediate reports
P Land based hourly specials
S Floating platforms (ship, buoy, etc.)
R Hydrologic reports
X Other surface data
Z Bulletins with mixed data type reports
T1 = I Observational Data
and
T2 = U Upper Air
Designator Data type
A Single level aircraft reports
B Single level balloon reports
C Single level satellite derived reports
D Dropsonde/dropwindsondes
M Model derived sondes
N Rocketsondes
P Profilers
R Radiance data
S Radiosondes/pibal reports
T Satellite derived sondes
X Other upper air reports
Z Mixed upper air reports
T2 = T TEXT
Designator Data type
A Administrative message
B Service message
R Request for data (inclusive of type)
X Other text messages of information
Z Mixed text types
T1 = I Observational Data
and
T2 = P PICTORIAL
Designator Data type
I Satellite imagery data
R Radar reports
X Not defined
Z Mixed data types
T1 = I or J Observational Data / Forecast Products)
and
T2 = O Oceanographic/Limnographic
Designator Data type
I Sea ice
S Sea surface and below soundings
T Sea surface temperature
W Sea surface waves
X Other sea environmental
Z Mixed collection of oceanographic types
T1 = J (Forecast Products)
and
T2 = S Surface/Sea Level
Designator Data type
A Surface area forecast (e.g. airway)
M Surface forecast (e.g. MOS)
P Forecast amendments (e.g. airways)
R Hydrologic forecast
S Forecast amendments (TAF)
T Aerodrome forecast (TAF)
X Other surface forecasts
Z Mixed collection of forecast types
T1 = J (Forecast Products)
and
T2 = U Upper Air
Designator Data type
A Forecast at single levels
S Forecast soundings
X Other upper air forecasts
Z Mixed collection of forecast types
T1 = J (Forecast Products)
and
T2 = T TEXT WARNINGS/Notices
Designator Data type
E Tsunami
H Hurricane, typhoon, tropical storm warning
S Severe weather, SIGMET
T Tornado warning
X Other warnings
Z Mixed collection of warnings
-----------------------------------------------------------------
Table C7
Data Type Designator A1 for Values of T2 = S, U, O, F, and V
( when T1 = K - CREX )
CBS XI, Cairo 1996
1. The designators specified in this table should be used to the
greatest extent possible to indicate the CREX type of
observational data contained within the body of the bulletin.
2. When the table does not contain a suitable designator for the
observational data type, an alphabetic designator which is not
assigned in the table should be introduced and the WMO Secretariat
notified.
3. In the event no standard format has been established for a
particular data type, and there is a recommended format, that
format is given in square brackets under the column labeled Code
Form (e.g. [ASCII]). This is a character code - International
Alphabet No.5 (Attachment II-2) will be used.
T2 = S Surface
A1
Designator Data type Code Form (CREX)
A Land based hourly reports [ASCII]
C Climatic reports [ASCII]
I Land intermediate synoptic reports [ASCII]
M Land based main synoptic reports [ASCII]
N Asynoptic intermediate reports [ASCII]
P Land based hourly specials [ASCII]
S Floating platforms (ship, buoy, etc.) [ASCII]
R Hydrologic reports [ASCII]
X Other surface reports [ASCII]
Z CREX bulletins with mixed data type rpts [ASCII]
T2 = U Upper Air
A1
Designator Data type Code Form (CREX)
A Single Level aircraft reports [ASCII]
B Single level balloon reports [ASCII]
C Single level satellite derived reports [ASCII]
D Dropsondes/dropwindsondes [ASCII]
L Ozone data [ASCII]
N Rocketsondes [ASCII]
P Profiler [ASCII]
R Radiance data [ASCII]
S Radiosonde/pibal [ASCII]
T Satellite derived sondes [ASCII]
X Other upper air reports [ASCII]
Z Mixed upper air data type reports [ASCII]
T2 = O Oceanographic/Liminographic
A1
Designator Data type Code Form (CREX)
I Sea Ice [ASCII]
S Sea surface and below sounding [ASCII]
T Sea surface temperature [ASCII]
W Sea surface waves [ASCII]
X Other sea environmental [ASCII]
Z Mixed collection of oceanographic types [ASCII]
T2 = F FORECASTS - Surface/Sea Level
A1
Designator Data type Code Form (CREX)
A Surface area forecast (e.g. airways) [ASCII]
M Surface forecasts (e.g. MOS) [ASCII]
P Forecast amendments (airways) [ASCII]
R Hydrologic forecasts [ASCII]
S Forecast amendments (TAF) [ASCII]
T Aerodrome forecasts (TAF) [ASCII]
X Other surface forecasts [ASCII]
Z Mixed collection of forecasts [ASCII]
T2 = V FORECASTS - Upper Air
A1
Designator Data type Code Form (CREX)
A Single level [ASCII]
S Soundings [ASCII]
X Other upper air forecasts [ASCII]
Z Mixed collection of forecasts [ASCII]
Note: The allocation of abbreviated headings for CREX messages is
pending the formal approval of the code CREX.
-----------------------------------------------------------------
Table D1
Level Designators
(ii when T1=O)
98 Surface
96 2.5
94 5.0
92 7.5
90 12.5
88 17.5
86 25.0
84 32.5
82 40.0
80 50.0
78 62.5
76 75.0
74 100
72 125
70 150
68 200
66 300
64 400
62 500
60 600
58 700
56 800
54 900
52 1000
50 1100
48 1200
46 1300
44 1400
42 1500
40 1750
38 2000
36 2500
34 3000
32 4000
30 5000
01 Primary layer depth
----------------------------------------------------------------
Table D2
Level Designators
(ii when T1= D,G,H,P,Q,X or Y)
99 1000 hPa
98 Air properties for the earth's surface
97 Level of the tropopause
96 Level of maximum wind
95 950 hPa
94 Level of 0oC isotherm
93 Not assigned - 975 hPa(U.S. use)
92 925 hPa
91 Not assigned - 875 hPa(U.S. use)
90 900 hPa
89 Any parameter reduced/sea level (MSLP)
88 Ground/water properties for the earth's
surface (i.e. snow cover, wave & swell)
87 1000-500 hPa thickness
86 Boundary Layer
85-01 Hundreds and tens digits of the hectopascal
level (e.g. 70 = 700 hPa;03 = 030 hPa)
TO INCLUDE:
81 = 810 hPa = 6000ft FL
82 = 825 hPa(U.S. use)
77 = 775 hPa(U.S. use)
73 = 730 hPa = 9000ft FL
72 = 725 hPa(U.S. use)
67 = 675 hPa(U.S. use)
65 = 650 hPa = 12000ft FL
62 = 625 hPa(U.S. use)
00 Entire Atmosphere (e.g. precipitable water)
US Tables
---------
Table B6
Data Type designator T2
( when T1 = Y or Z )
U.S. Table for National GRIB Products
U.S. National Practice
1. The designator specified in this table should be used to the
greatest extent possible to indicate the data types of the data
contained within the text of the bulletin.
2. Where the data type does not correspond exactly with the
designator, the designator for the most approximate type of the
data may be used.
3. The NWS will assign designators to this table in place of the
unassigned designators when needed.
Designator Data Type
A Cloud parameters (ice, water)
B Vertical Wind Shear
C Vorticity
D Probability Values (Thunderstorm, Precip types,
Cloud types)
E Precipitation parameters (Precip. water,
convective Precip.)
F Long wave radiation
G Temperature Values (Maximum, Minimum, Dew Point)
H Height (geopotential)
I unassigned
J unassigned
K Ocean wave properties (Period, Direction)
L unassigned
M unassigned
N unassigned
O Vertical velocity/Surface Lifted index
P Pressure
Q Stability Index
R Relative humidity
S Snow properties
T Temperature
U Wind components (U V)
V unassigned
W Cape/Cin/Helicity
X-Z unassigned
------------------------------------------------------------------
Table C8
Geographical area designator A1
(when T1 = H)
U.S. National Table derived from WMO Table C3
1. The designator specified in this table should be used to the
greatest extent possible to indicate the geographical area of the
data contained within the text of the bulletin.
2. Where the geographical area of the data does not correspond
exactly with the designator, the designator for the area most
approximating that of the data may be used.
3. When the table does not contain a suitable designator for the
geographical area, an alphabetic designator which is not assigned
in the table will be introduced.
Designator Geographical Area
A 0 - 180 E northern hemisphere [21]
B 180 W - 0 northern hemisphere [22]
C 0 - 180 E southern hemisphere [23]
D 180 W - 0 southern hemisphere [24]
E 0 - 355 E northern hemisphere [25]
F 0 - 355 E southern hemisphere [26]
G Regional use
H Not Assigned
I 30 W - 60 E northern hemisphere [37]
J 60 W - 150 E northern hemisphere [38]
K 150 E - 120 W northern hemisphere [39]
L 120 W - 30 W northern hemisphere [40]
M 30 W - 60 E southern hemisphere [41]
N 60 W - 150 E southern hemisphere [42]
O 150 E - 120 W southern hemisphere [43]
P 120 W - 30 W southern hemisphere [44]
Q-S Not Assigned
T 0 - 180 E northern hemisphere [61]
U 180 W - 0 northern hemisphere [62]
V 0 - 180 E southern hemisphere [63]
W 180 W - 0 southern hemisphere [64]
X Regional use
Y-Z Not Assigned
Geographical area designator A1
( when T1 = Y or Z )
Designator Geographical Area NCEP GRID No.
A northern hemisphere [201]
B unassigned
C unassigned
D unassigned
E unassigned
F unassigned
G unassigned
H National CONUS w/ Double Resolution [213]
I National CONUS [202]
J National Alaska [203]
K National Hawaii [204]
L National Puerto Rico [205]
M Regional MARD [206]
N Regional Alaska [207]
O Regional Hawaii [208]
P Regional Puerto Rico [210]
Q Regional CONUS [211]
R Regional CONUS w/ Double Resolution [212]
S Regional MARD w/ Double Resolution [209]
T Regional Alaska w/ Double Resolution [214]
U Regional CONUS [215]
V Regional Alaska [216]
W-Z unassigned
------------------------------------------------------------------
Table C9
Geographical-Tile Number designator T2 A1
( when T1 = Z and the CCCC = KWBZ)
( A DRAFT U.S. National Practice Table )
Instructions for the proper application of the Geographical "TILE"
number designator - A two character field of the heading.
1. The designator specified in this table should be used to the
greatest extent possible to indicate the geographical high
resolution grid tile number of the data contained within the
geographical area as specified by the grid squares defined by the
producing center of the GRIB bulletin.
2. Where the geographical tile number for the area of the data
does not correspond exactly with the designator, the number
designator for the area most approximating that area of the data
may be used. The exact area of coverage will be available within
the GRIB Product Definition Section (PDS) of the bulletin.
Designator Geographical Area Tile Number NCEP Model
AA - AW 01 - 24 CONUS 20 km tiles meso-Eta
AY - AZ unassigned
BA - BW 01 - 24 CONUS 20 km tiles RUC
BY - BZ unassigned
CA - CW unassigned
CY - CZ unassigned
DA - DZ unassigned
EA - EZ unassigned
FA - FZ unassigned
GA - GZ unassigned
HA - KR 01 - 96 CONUS 10 km tiles meso-Eta
KS - KZ 01 - 08 Alaska 20 km tiles RUC
LA - OR 01 - 96 CONUS 10 km tiles RUC
OS - OZ 01 - 08 Hawaii 20 km tiles RUC
PA - QZ unassigned
RA - RF 01 - 06 CONUS 40 km tiles meso-Eta
RG - RL 01 - 06 CONUS 40 km tiles RUC
RM - RR 01 - 06 Alaska 40 km tiles meso-Eta
RS - RX 01 - 06 Alaska 40 km tiles RUC
RY - RZ unassigned
SA - SF 01 - 06 Hawaii 40 km tiles meso-Eta
SG - SL 01 - 06 Hawaii 40 km tiles RUC
SM - ZZ unassigned
-----------------------------------------------------------------
Table C10
Reference Time designator A2
(when T1 = Y or Z)
1. The designator specified in this table should be used to the
greatest extent possible to indicate the reference time of data
contained within the text of the bulletin.
2. When the table does not contain a suitable designator for the
reference time, use "Z" and obtain the forecast hour from the GRIB
Product Definition Section.
Designator Data Type Designator Data Type
A Analysis (00 hour) N 18 hours forecast
B 1 hour forecast O 24 hours forecast
C 2 hours forecast P 30 hours forecast
D 3 hours forecast Q 36 hours forecast
E 4 hours forecast R 42 hours forecast
F 5 hours forecast S 48 hours forecast (2 days)
G 6 hours forecast T 60 hours forecast
H 7 hours forecast U 72 hours forecast (3 days)
I 8 hours forecast V 84 hours forecast
J 9 hours forecast W 96 hours forecast (4 days)
K 10 hours forecast X 108 hours forecast
L 11 hours forecast Y 120 hours forecast (5 days)
M 12 hours forecast Z Time contained in PD Block
of GRIB code
---------------------------------------------------------------------
Table D3
Level designator ii
(when T1 = H, X, Y, or Z)
(U.S. National Practice definitions included)
Instructions for the proper application of level (elevations above
the earth's surface) designator.
1. The designator specified in this table should be used to the
greatest extent possible to indicate the level of the data
contained within the text of the bulletin.
2. When data at more than one level are contained in the text, the
designator for only one of the levels should be used.
3. When the table does not contain a suitable designator for the
level, a designator which is not assigned in the table should be
used.
The U.S. Practice uses 25 mb increments 1000-100 mb and are
included below.
ii
Designator Level
00 Entire Atmosphere (e.g. precipitable water)
99 1000 hPa
98 Air properties for the earth's surface
97 Level of the tropopause
96 Level of maximum wind
95 950 hPa
94 Level of 0oC isotherm
93 975 hPa
92 925 hPa
91 875 hPa
90 900 hPa
89 Any parameter reduced/sea level (MSLP)
88 Ground/water properties for the earth's
surface (i.e. snow cover, wave & swell)
87 1000-500 hPa thickness
86 Boundary Layer
74 Cloud top level
85-01 Hundreds and tens digits of the hectopascal
level(e.g. 70=700 hPa;03=030 hPa)
TO INCLUDE:
81 = 810 hPa = 6000ft FL
82 = 825 hPa
84 = 875 hPa
77 = 775 hPa
73 = 730 hPa = 9000ft FL
72 = 725 hPa
67 = 675 hPa
65 = 650 hPa = 12000ft FL
62 = 625 hPa
50 = 510 hPa = 18000ft FL (U.S. National
Practice uses 500 mb level)
11 = First 30 mb average thickness [from
surface]
12 = Second 30 mb average thickness
13 = Third 30 mb average thickness
14 = Forth 30 mb average thickness
45 = Fifth 30 mb average thickness
16 = Sixth 30 mb average thickness
Note: The 810, 730, and 650 hPa levels are not being used as
pressure levels, they are being used as geometric heights.
<top>
Appendix #2: What BBB Codes Mean
================================
GUIDELINES on the USE of the INDICATOR BBB
T1T2A1A2ii CCCC YYGGgg (BBB)
This line, which is preceded by "format effectors" [ cr ] [ cr ] [
lf ], constitutes the complete WMO abbreviated heading line, which
can contain the optional BBB group, indicated by the open and
closed parenthesis ( ).
General Instructions
The WMO abbreviated heading line, including each unique YYGGgg
(date time group), shall be used only once a month, due to the day
of the month being part of the heading. The indicator BBB shall
only be added when a WMO abbreviated heading has already been used
for transmission of an initial bulletin. It indicates that the
contents to be a delayed, corrected or amended bulletin. The
indicator BBB can also be used for segmentation as described below
in paragraph 5.
The indicator BBB shall only be included in the WMO abbreviated
headings of delayed (retard), corrected, or amended bulletins by
those centres which are responsible for preparing, or compiling
the bulletins concerned, or for communication transmission reasons
by any system as a segment sequence indicator when bulletins are
segmented to control bulletin size.
Once the initial bulletin has been transmitted, the centre
responsible for preparing or compiling the original bulletin uses
the indicator BBB to transmit delayed or corrected reports or to
amend information for the same abbreviated heading containing the
same YYGGgg.
A centre shall not construct an abbreviated heading with the
indicator BBB for delayed, corrected, amended, bulletins having a
size larger than the limit defined in TABLE A as it would cause a
communications system to segment it before transmission.
The Bulletin Segment Heading is a special form of the WMO
abbreviated heading where the indicator BBB takes the form of Pxx.
The bulletin segment heading replaces the normal WMO abbreviated
heading when bulletins are larger than size limit defined in WMO
Table A. The bulletin segment heading shall take the place of the
WMO abbreviated heading for electronic transmission purposes. The
bulletin segment heading is a repeating heading, with a unique Pxx
group for each segment. The original WMO bulletin shall be re-
constructed from these segments before use.
The bulletin segment heading cannot be used in place of a standard
WMO abbreviated heading of a bulletin if any of the other
indicator BBB options are present. This normally will not be a
problem as a delayed, corrected, or amended bulletin with the
indicator BBB should be smaller then the initial message. However,
the U.S. has established a National practice to support the
transmission of plain text bulletins containing an abbreviated
heading with a BBB group which are too large for transmission.
BBB Forms
The four forms of the BBB indicator group are:
RRx - Delayed (Retard)
CCx - Correction
AAx - Amendment
Pxx - Segment number
Each form precludes the use of the others in the same bulletin.
The RRx, CCx, and AAx forms are attributes of the content of the
bulletin, and the Pxx is an attribute of the segment number not
the content. Each form is described separately below.
RRx Indicator Group - Delayed Routine Meteorological Reports
[retard]
This indicator group has the form RRx; where: x = A through X. It
is used to transmit a collection of one or more weather reports
which are normally contained in the initial bulletin but which
were received after the initial bulletin has been transmitted. The
value of x = A is for the first bulletin containing additional
reports; a value of x = B for a second bulletin containing
additional reports, if necessary, and, so on up to and including x
= X. For x = Y it represents a loss of the record of the sequence
by the issuing center. For x = Z it represents the compiled
bulletin is over 24 hours after the time of observation.
CCx Indicator Group -Corrections to Previously Transmitted Reports
This indicator group has the form: CCx; where x = A through X. It
is used to transmit a bulletin containing corrections to reports
that have already been included in a bulletin previously
transmitted. The value of x = A is for the first bulletin
containing corrected reports; a value of x = B for a second
bulletin containing additional corrected reports, if necessary,
and, so on up to and including x = X. For x = Y it represents a
loss of the record of the sequence by the issuing center. For x =
Z it represents the compiled bulletin is over 24 hours after the
time of observation.
AAx Indicator Group - Amendments to Processed Information
This indicator group has the form AAx; where x = A through X. It
is used to transmit a bulletin containing amendments to processed
information in a bulletin which has previously been sent. The
value of x = A is for the first bulletin containing information
amending the basic (initial) bulletin; a value of x = B for a
second bulletin containing information amending the basic
(initial) bulletin, if necessary, and so on up to and including x
= X. For x = Y it represents a loss of the record of the sequence
by the issuing center. For x = Z it represents the compiled
bulletin is over 24 hours after the time of observation.
Pxx Indicator Group - Segmentation of a Large Bulletin
When a bulletin exceeds the length limit defined in Table A, it
shall be segmented for communications purposes using a bulletin
segment heading line utilizing the Pxx Indicator Group. There are
two different structures possible for segments. Segmented
alphanumeric products have a supplementary identification line
which repeats information in addition to the bulletin segment
heading line in each segment. Segmented binary products do not
repeat the supplementary identification line information in a
second line for each subsequent segment. Only the bulletin segment
heading line is repeated.
Defining:
Pxx = values of xx = AA through YZ and ZA through ZZ
The following principles shall apply when segmenting alphanumeric
bulletins for transmission:
The first bulletin segment heading will have sequence indicator xx
= AA, the second AB and so on up to the last bulletin segment
heading which shall have xx = Zx.
The Z is a LAST SEGMENT FLAG and is placed in the first x position
of the Pxx group of the last segment of the set of bulletin
segments with the second x the sequence letter which would have
normally been used if this was not the last segment.
This special PZx group is required to inform the receiving center
that no more bulletin segments exist for this product.
And;
Any original code form or product identification indicator shall
be included in each bulletin segment heading and is called a
supplementary identification line.
Except for the last segment, segment lengths shall be as long as
possible, within approved bulletin length limits [Table A] and
formatting constraints.
Segmented bulletin breaks shall immediately follow end-of-report
indicator signals ( = signs ) when or where available in close
proximity to the size limit. When end-of report indicators can't
be used, segmented plain text bulletins will be broken on an end-
of-line function or on a space if the end-of-line function can not
be found in close proximity to the size limit.
All WMO Regional Telecommunication Hubs on the Global
Telecommunication System should relay bulletin segments as
received on the Main Trunk Network.
Upon receipt all plain text bulletin segments the receiving end
shall re-built the original bulletin prior to use, as the
segmentation procedure is for transmission purposes only.
Bulletin segments must be processed to re-build the original
bulletin to obtain a complete plain text product.
U.S. National Practice
If it is necessary to segment a bulletin which exceeds the limits
established by WMO and the bulletin already utilizes a bulletin
attribute (BBB), the following procedures will be used. A bulletin
segmentation heading including the appropriate Pxx indicator group
will be used; and the original bulletin attribute (BBB) will be
included as a separate line followed immediately by the line
function carriage return, carriage return, line feed in the first
segment only. (see examples below)
Binary Bulletins
The following principles shall apply when segmenting binary
bulletins (i.e. GRIB, BUFR, and T4 FAX bulletins):
Bulletin segment lengths shall be as long as possible, as allowed
by approved bulletin length limits (except for the last segment)
RTHs should relay bulletin segments as received
An example of the segmentation of a T4 FAX WMO bulletin that has
been received too large according to Table A for onward
transmission without segmentation:
Example:
FIRST BULLETIN SEGMENT
PGEE25 KWBC 181200 PAA
DFAX 1064 bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
bbbbbbbbbbbbbbbbbbbbbbb .....etc...
[ until 15000 octets have been reached ]
SECOND BULLETIN SEGMENT
PGEE25 KWBC 181200 PAB
bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
bbbbbbbbbbbbbbbbbbbbbbbb .....etc...
[ until 15000 octets have been reached ]
THIRD BULLETIN SEGMENT
PGEE25 KWBC 181200 PAC
bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
bbbbbbbbbbbbbbbbbbbbbbbb .....etc...
[ until 15000 octets have been reached ]
FOURTH and LAST BULLETIN SEGMENT
PGEE25 KWBC 181200 PZD
bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
bbbbbbbbbbbbbbbbbbbbbbbb .....etc...
[ until something less than 15000 octets have been reached ]
Warning !
Bulletin segments must be processed to re-build the original
bulletin from it's segment parts to be able to obtain the complete
binary bulletin prior to further use.
All binary bulletins greater than 15,000 bytes will be segmented
unless prior mutual agreement between adjacent centers has
established otherwise. The segments will be based upon size only
and no consideration will be given to where the break occurs.
Bulletin segments will have no additional information added beyond
the bulletin segment heading line itself, containing the BBB group
of Pxx to accomplish the segmentation process.
Additional comments on the use of the BBB groups.
An RTH on the GTS should ensure the relay of any bulletins
received in accordance with its routing directories even if the
bulletins are in fact bulletin segment heading lines and have not
been received in the correct sequence. All the bulletin segments
containing the indicator Pxx shall be relayed to enable the end
user to reconstruct and use the original bulletin.
In case of incomplete or incorrect reception, the use of the
addressed message for request/reply may be required for recovering
incomplete or incorrect bulletin(s). The request for a bulletin
segment may be acceptable, or the request for the repeated
transmission of the entire set of information (i.e. the whole
sequence of bulletin segments) may be necessary, in which case the
indicator Pxx would not be used in the request.
<top>
Appendix #3: The METAR Code
===========================
METAR was adopted in 1996 as the world standard, replacing the
Airways Code used in the US. More recently, such US broadcasts as
ATIS and VOLMET have gone to the METAR form for reporting
observations. The biggest change is the use of Celsius for
temperature in the US. Exceptions to the international standard
allow for the use of feet, inches, and statute miles for other
observations.
American observations will never have QNH (surface pressure in
hectopascals or millibars), while European and other foreign ones
usually do, and this is one way to tell them in voice weather
traffic such as VOLMET.
Although not used in the US, "Ceiling And Visibility OK"
(CAVOK) replaces visibility, weather and clouds if:
1) visibility greater than or equal to 10 kilometers;
2) no clouds below 1500 meters or below the highest minimum
sector altitude, whichever is greater and no CB; and
3) no precipitation, TS, DS, SS, MIFG, DRDU, DRSA, or DRSN.
METAR Format (FM-15)
Surface Meteorological Airways Format
Syntax:
METAR CCCC TIME AUTO WIND VISIBILITY WEATHER CLOUDS TEMP/DEW
ALTIMETER REMARKS
METAR
This defines the product type.
METAR regularly reported observation (such as an hourly)
SPECI special observation
TESTM non-commissioned ASOS report
CCCC
CCCC is the 4 letter ICAO ID uniquely defining the reporting
station.
CONUS sites begin with 'K', Alaskan sites begin with 'PA',
Hawaiian sites begin with 'PH', Canadian sites begin with 'C',
Mexican sites begin with 'MM'
TIME
The full universal time (UTC) that the observation was taken. The
format is:
ddhhmmZ.
dd is the day of the month, hh is the hour, mm is the minute.
Z refers to Zulu time.
AUTO
This is an optional grouping used in the US to specify a station
as being automated.
COR
This is an optional grouping used in the US to specify an
observation as being corrected.
WIND
The wind group
dddssKT or dddssGggKT
The value ddd is the wind direction in degrees. The value ss is
the wind speed. The units are defined by the string "KT" which is
knots. Some reports may have "MPS" for meters per second. If wind
gusts are reported, they are specified with the group "Ggg".
VISIBILITY
The visibility group
vvSM or vvKM
This specifies the visibility is either statue miles "SM" (US), or
kilometers "KM". The visibility can be partial values such as "1
1/2SM" or "3/16SM". Optionally a 4-digit minimum visibility in
meters and as required, lowest value with direction.
RR/xxxx xxxx
Runway Visual Range (optional)
R; 2-digit runway designator; Left, Center, or Right as
needed; "/"; Minus or Plus (as needed); in U.S, 4-digit value;
FeeT in U.S. ; as needed, 4-digit value;
Variability; 4-digit value (and tendency Down, Up or No change)
WEATHER
The weather group
iiddppooxx
ii is intensity group ii Description
- light
moderate
+ heavy
VC in the vicinity
dd is the descriptor group dd Description
MI shallow
PR partial
BC patches
DR low drifting
BL blowing
SH shower
TS thunderstorm
FZ freezing
pp is the precipitation group pp Description
DZ drizzle
RA rain
SN snow
SG snow grains
IC ice crystals
PE ice pellets
GR hail
GS small hail/snow pellets
UP unknown
oo is the obscuration group oo Description
BR mist
FG fog
FU smoke
VA volcanic ash
DU dust
SA sand
HZ haze
PY spray
xx is the misc group xx Description
PO dust whirls
SQ squalls
FC funnel cloud/tornado/waterspout
SS duststorm
CLOUDS
The cloud levels
ccchhhtt
ccc is the coverage
CLR or SKC = clear
FEW = 1/8 coverage
SCT = 2,3,4/8 coverage
BKN = 5,6,7/8 coverage
OVC = overcast
VV = vertical visibility for obscuration
hhh is the height of base in 30m or 100ft increments. ie 30 = 3000
feet
tt is an optional type
CU = cumulus
CB = cumulonimbus
TCU = towering cumulus
CI = cirrus
CAVOK = clear skies, unlimited visibility
CAVOK is a widely used national practice, though not in the US.
When placed in this group, it means Clouds And Visibility OK.
Often NOSIG (No Siginficant features/changes)is placed in the
comment field to indicate that this condition will not change for
two hours.
In automated METAR reports only, CLeaR means "clear below 12,000
feet"
TEMP/DEW
is the temperature and dewpoint in Celsius
TT/DD
negative values are preceded with a M (M03 = -3)
ALTIMETER
is the altimeter setting
Qpppp = altimeter in whole mb
Apppp = altimeter in .01 in Hg
REMARKS
The remark section:
RMK xxxx xxxx xxxx...
Remark Description
AO1 AMOS station
AO2 ASOS station
OBS TAKEN +xx minute offset for observation time
SLPppp Sea level pressure in .1 mb (142 = 1014.2 mb)
WEA:www Additional present weather information
Tttttdddd Current temperature/dewpoint in .1C
first digit 1 for negative
1xxxx 6 hour max temp in .1C, first digit 1 for
negative
2nnnn 6 hour min temp in .1C, first digit 1 for
negative
4/sss Snow coverage in inches
4xxxxnnnn 24 hour max/min temps in .1C, first digit 1 for
negative
5tppp Pressure tendency in .1 mb for 3 hours, t is the
trend
6pppp 6 hour precipitation in .01 inches
7pppp 24 hour precipitation in .01 inches
8/lmh Cloud type for low, medium, high
933sss New snow coverage, water equivalent
98mmm Equivalent sunshine for day in minutes
CITY tt City temperature
PCPN pppp
Ppppp 1 hour precipitation
PK WND sss/nn Peak wind, sss is speed, nn is the time
PRESFR Pressure falling rapidly
PRESRR Pressure rising rapidly
SNOINCR xxx Snow increasing rapidly,
where xxx is amount of snow in last hour
TSNO Automated station has no thunderstorm detector (US)
WSHFT nn Wind shift at time nn
<top>
Appendix #4: SYNOP Code
=======================
SYNOP Data Format (FM-12)
Surface Synoptic Observations
SYNOP code is the WMO standard method for transmitting surface
weather information. It is universal in that separate optional
formats exist for different units of measurement. The entire
content, except for some plain-text ICE observations, is numeric,
and that the format never varies beyond basic standard departures
authorized for individual countries.
SYNOP is not as easy to read as METAR, but it is easier for a
computer to encode and decode. Many programs exist to do just
that. Unfortunately, SYNOP codes change frequently, keeping
computer programmers on their toes.
The official reference for any surface observer in the United
States is the Federal Meteorological Handbook No. 1, published
jointly by the US Departments of Commerce (NWS), Transportation
(FAA), and Defense (AWS/Navy). The complete synoptic code is
described in the Federal Meteorological Handbook No. 2 (same
publishers as above).
The coded report is given in six groups of data, or sections.
Sections 0 and 1 are not identified by any special identifying
groups, but Sections 2, 3, and 5 are recognizable by the 222, 333,
or 555 included as part of the message (Section 4 is not used in
the US). Surface marine data (from buoys which report hourly and
ships-of-opportunity and weather ships, which report every 6
hours) are found in section 2, which contains reporting formats
peculiar to the SHIP code.
Several forms of the observation were changed in the late 1990s
and are not reflected in most online decoders. These include the
10 m and 20 m wind speed estimates (11 and 22 groups), time and
values of maximum winds (3 & 4 groups in section 5), and 10-minute
average winds, beginning at the time of observation and working
backwards in time (the last 6 groups of section 5 in the CMAN
code).
000 Group - Identification and Location
111 Group - Land Observations
222 Group - Sea Surface Observations
333 Group - Climatological Data
444 Group - Clouds below a mountain station, not used in US
555 Group - National Practice Observations
Groups 0 and 1 have no beginning designators, but the others, when
present will be 222, 333, and 555.
Not all groups need occur in all SYNOP. Land stations will
obviously not need group 2.
Syntax;
IIiii or IIIII YYGGi 99LLL QLLLL
iihVV Nddff 00fff 1sTTT 2sTTT 3PPPP 4PPPP 5appp 6RRRt 7wwWW 8NCCC
9GGgg
222Dv 0sTTT 1PPHH 2PPHH 3dddd 4PPHH 5PPHH 6IEER 70HHH 8aTTT
333 0.... 1sTTT 2sTTT 3Ejjj 4Esss 5jjjj jjjjj 6RRRt 7RRRR 8Nchh
9SSss
444 Not usually used
555 National practice - varies
Section 0: Station & Date/time information
------------------------------------------
IIiii or IIIII YYGGi 99LLL QLLLL
For land stations :
AAXX YYGGiw IIiii
For land stations, the AAXX indicates that the report type
follows the WMO SYNOP FM-12 code. Land stations provide the
date/time group as do ship stations (see above) through the YYGGiw
group. This message usually appears at the start of a bulletin
which may contain many reports (see example below). The IIiii
group is for the WMO block number (II) and station number (iii)
within each block.
In the US, the block numbers are:
41 Tropical North Atlantic Ocean (buoys)
42 Gulf of Mexico (buoys)
44 Extratropical N Atlantic Ocean (buoys)
45 Great Lakes (buoys)
46 Tropical NE Pacific Ocean (buoys)
51 Extratropical NE Pacific Ocean (buoys)
70 Alaska
71 Canada
72 Contiguous US (civilian)
74 US (military)*
76 Mexico
78 Central America and Caribbean
80 South America/Caribbean stations
91 Hawaii and US Pacific territories
WMO station numbers generally start with 200 and increase to
the west along a latitude band, and then at 300 you move up the
next latitude band, on the eastern edge of the block number, etc.
The southeastern US has station numbers in the low 200's and the
Pacific Northwest has station numbers in the high 700's.
For ships :
BBXX DDDD YYGGiw 99LaLaLa QcLoLoLoLo
WMO SYNOP FM-13 is the standard reference for ship SYNOP, which
will be designated in the heading by BBXX. It is published in the
US by the Navy, and it is also available several places online.
SYNOP, like METAR, can also be decoded online.
Since buoys are fixed ships, they provide latitude and
longitude positions, but also use a WMO station number format
(IIiii) rather than the ship ID format DDDD. CMAN (coastal-marine)
stations are special types of automated observing stations
installed primarily to replace the old lighthouse stations which
were staffed by Coast Guard observers. These stations also report
in the synoptic code format.
IIiii The WMO number of the station.
Ship or Buoy Observations:
IIIII The ship or buoy identifier
YYGGi
YY -- The day of the month
GG -- The hour of the observation (UTC)
iw -- Wind type indicator
0 -- m/s (estimated)
1 -- m/s (from anemometer)
2 -- knots (estimated)
3 -- knots (from anemometer)
99LLL QLLLL
LLL -- Latitude of observation to .1 degrees
Q -- Quadrant of observation
1 -- North east
3 -- South east
5 -- South west
7 -- North west
LLLL -- Longitude of observation to .1 degrees
Section 1: International Land Observations
------------------------------------------
iRixhVV Nddff 1snTTT 2snTdTdTd 3PoPoPoPo 4PPPP
5appp 6RRRtR 7wwW1W2 8NhCLCMCH 9GGgg
111 Group - Land Observations
iihVV
iR -- Precipitation indicator
0 -- Precipitation in groups 1 and 3
1 -- Precipitation reported in group 1 only
2 -- Precipitation reported in group 3 only
3 -- Precipitation omitted, no precipitation
4 -- Precipitation omitted, no observation
ix -- Station type and present and past weather indicator
1 -- manned station -- weather group included
2 -- manned station -- omitted, no significant weather
3 -- manned station -- omitted, no weather observation
4 -- automated station -- weather group included (see automated
weather codes 4677 and 4561)
5 -- automated station -- omitted, no significant weather
6 -- automated station -- omitted, no weather observation
7 -- automated station -- weather group included (see automated
weather codes 4680 and 4531)
h -- Cloud base of lowest cloud seen (meters above ground)
0 -- 0 to 50 m
1 -- 50 to 100 m
2 -- 100 to 200 m
3 -- 200 to 300 m
4 -- 300 to 600 m
5 -- 600 to 1000 m
6 -- 1000 to 1500 m
7 -- 1500 to 2000 m
8 -- 2000 to 2500 m
9 -- above 2500 m
/ -- unknown
VV -- Visibility
00 -- less than 0.1 km
01 -- 0.1 km
02 -- 0.2 km
...
50 -- 5.0 km
56 -- 6 km
57 -- 7 km
...
80 -- 30 km
81 -- 35 km
82 -- 40 km
83 -- 45 km
84 -- 50 km
85 -- 55 km
86 -- 60 km
87 -- 65 km
88 -- 70 km
89 -- greater than 70 km
90 -- less than 0.05 km
91 -- 0.05 km
92 -- 0.2 km
93 -- 0.5 km
94 -- 1 km
95 -- 2 km
96 -- 4 km
97 -- 10 km
98 -- 20 km
99 -- greater than 50 km
// -- missing
Nddff
N -- Total cloud cover
0 -- 0 eighths (clear)
1 -- 1/8th
2 -- 2/8ths
3 -- 3/8ths
4 -- 4/8ths
5 -- 5/8ths
6 -- 6/8ths
7 -- 7/8ths
8 -- 8/8ths (overcast)
9 -- sky obscured
/ -- no observation
dd -- wind direction in 10s of degrees
ff -- wind speed in units determined by wind type indicator (see
above)
00fff (optional)
fff -- wind speed if value greater than 100
1sTTT -- Temperature
s -- sign of temperature (0=positive, 1=negative)
TTT -- Temperature in .1 C
2sTTT -- Dewpoint
s -- sign of temperature (0=positive, 1=negative, 9 = RH)
TTT -- Dewpoint temperature in .1 C (if sign is 9, TTT is relative
humidity)
3PPPP -- Station pressure in 0.1 mb (thousandths digit omitted,
last digit can be slash, then pressure in full mb)
4PPPP -- Sea level pressure in 0.1 mb (thousandths digit omitted,
last digit can be slash, then pressure in full mb)
4ahhh -- Geopotential of nearest mandatory pressure level (use for
high altitude stations where sea level pressure reduction is not
accurate)
a3 -- mandatory pressure level
1 -- 1000 mb
2 -- 925 mb
5 -- 500 mb
7 -- 700 mb
8 -- 850 mb
hhh -- geopotential height omitting thousandths digit
5appp -- Pressure tendency over 3 hours
a -- characteristics of pressure tendency
0 -- Increasing, then decreasing -- resultant pressure same or
higher
1 -- Increasing, then steady -- resultant pressure higher
2 -- Increasing steadily -- resultant pressure higher
3 -- Decreasing or steady, then increasing -- resultant pressure
higher
4 -- Steady -- resultant pressure same
5 -- Decreasing, then increasing -- resultant pressure lower
6 -- Decreasing, then steady -- resultant pressure lower
7 -- Decreasing steadily -- resultant pressure lower
8 -- Increasing or steady, then decreasing -- resultant pressure
lower
ppp -- 3 hour pressure change in 0.1 mb
6RRRt -- Liquid precipitation
RRR -- Precipitation amount in mm
001 -- 1 mm
002 -- 2 mm
...
988 -- 988 mm
989 -- 989 or more mm
990 -- Trace
991 -- 0.1 mm
992 -- 0.2 mm
...
999 -- 0.9 mm
t -- Duration over which precipitation amount measured
1 -- 6 hours
2 -- 12 hours
3 -- 18 hours
4 -- 24 hours
5 -- 1 hour
6 -- 2 hours
7 -- 3 hours
8 -- 9 hours
9 -- 15 hours
/ -- 24 hours
7wwWW -- Present and past weather
ww -- Present weather
00 -- clear skies
01 -- clouds dissolving
02 -- state of sky unchanged
03 -- clouds developing
Haze, smoke, dust or sand
04 -- visibility reduced by smoke
05 -- haze
06 -- widespread dust in suspension not raised by wind
07 -- dust or sand raised by wind
08 -- well developed dust or sand whirls
09 -- dust or sand storm within sight but not at station
Non-precipitation events
10 -- mist
11 -- patches of shallow fog
12 -- continuous shallow fog
13 -- lightning visible, no thunder heard
14 -- precipitation within sight but not hitting ground
15 -- distant precipitation but not falling at station
16 -- nearby precipitation but not falling at station
17 -- thunderstorm but no precipitation falling at station
18 -- squalls within sight but no precipitation falling at station
19 -- funnel clouds within sight
Precipitation within past hour but not at observation time
20 -- drizzle
21 -- rain
22 -- snow
23 -- rain and snow
24 -- freezing rain
25 -- rain showers
26 -- snow showers
27 -- hail showers
28 -- fog
29 -- thunderstorms
Duststorm, sandstorm, drifting or blowing snow
30 -- slight to moderate duststorm, decreasing in intensity
31 -- slight to moderate duststorm, no change
32 -- slight to moderate duststorm, increasing in intensity
33 -- severe duststorm, decreasing in intensity
34 -- severe duststorm, no change
35 -- severe duststorm, increasing in intensity
36 -- slight to moderate drifting snow, below eye level
37 -- heavy drifting snow, below eye level
38 -- slight to moderate drifting snow, above eye level
39 -- heavy drifting snow, above eye level
Fog or ice fog
40 -- Fog at a distance
41 -- patches of fog
42 -- fog, sky visible, thinning
43 -- fog, sky not visible, thinning
44 -- fog, sky visible, no change
45 -- fog, sky not visible, no change
46 -- fog, sky visible, becoming thicker
47 -- fog, sky not visible, becoming thicker
48 -- fog, depositing rime, sky visible
49 -- fog, depositing rime, sky not visible
Drizzle
50 -- intermittent light drizzle
51 -- continuous light drizzle
52 -- intermittent moderate drizzle
53 -- continuous moderate drizzle
54 -- intermittent heavy drizzle
55 -- continuous heavy drizzle
56 -- light freezing drizzle
57 -- moderate to heavy freezing drizzle
58 -- light drizzle and rain
59 -- moderate to heavy drizzle and rain
Rain
60 -- intermittent light rain
61 -- continuous light rain
62 -- intermittent moderate rain
63 -- continuous moderate rain
64 -- intermittent heavy rain
65 -- continuous heavy rain
66 -- light freezing rain
67 -- moderate to heavy freezing rain
68 -- light rain and snow
69 -- moderate to heavy rain and snow
Snow
70 -- intermittent light snow
71 -- continuous light snow
72 -- intermittent moderate snow
73 -- continuous moderate snow
74 -- intermittent heavy snow
75 -- continuous heavy snow
76 -- diamond dust
77 -- snow grains
78 -- snow crystals
79 -- ice pellets
Showers
80 -- light rain showers
81 -- moderate to heavy rain showers
82 -- violent rain showers
83 -- light rain and snow showers
84 -- moderate to heavy rain and snow showers
85 -- light snow showers
86 -- moderate to heavy snow showers
87 -- light snow/ice pellet showers
88 -- moderate to heavy snow/ice pellet showers
89 -- light hail showers
90 -- moderate to heavy hail showers
Thunderstorms
91 -- thunderstorm in past hour, currently only light rain
92 -- thunderstorm in past hour, currently only moderate to heavy
rain
93 -- thunderstorm in past hour, currently only light snow or
rain/snow mix
94 -- thunderstorm in past hour, currently only moderate to heavy
snow or rain/snow mix
95 -- light to moderate thunderstorm
96 -- light to moderate thunderstorm with hail
97 -- heavy thunderstorm
98 -- heavy thunderstorm with duststorm
99 -- heavy thunderstorm with hail
W1 -- Past weather (type 1)
W2 -- Past weather (type 2)
0 -- cloud covering less than half of sky
1 -- cloud covering more than half of sky during part of period
and more than half during part of period
2 -- cloud covering more than half of sky
3 -- sandstorm, duststorm or blowing snow
4 -- fog, or thick haze
5 -- drizzle
6 -- rain
7 -- snow or mixed rain and snow
8 -- showers
9 -- thunderstorms
8NCCC -- Cloud type information
N -- Amount of low clouds covering sky, if no low clouds, the
amount of the middle clouds
CL -- Low cloud type
0 -- no low clouds
1 -- cumulus humulis or fractus (no vertical development)
2 -- cumulus mediocris or congestus (moderate vertical
development)
3 -- cumulonimbus calvus (no outlines nor anvil)
4 -- stratocumulus cumulogenitus (formed by spreading of cumulus)
5 -- stratocumulus
6 -- stratus nebulosus (continuous sheet)
7 -- stratus or cumulus fractus (bad weather)
8 -- cumulus and stratocumulus (multilevel)
9 -- cumulonimbus with anvil
/ -- low clouds unobserved due to darkness or obscuration
CM -- Middle cloud type
0 -- no middle clouds
1 -- altostratus translucidous (mostly transparent)
2 -- altostratus opacus or nimbostratus
3 -- altocumulus translucidous (mostly transparent)
4 -- patches of altocumulus (irregular, lenticular)
5 -- bands of altocumulus
6 -- altocumulus cumulogenitus (formed by spreading of cumulus)
7 -- altocumulus (multilayers)
8 -- altocumulus castellanus (having cumuliform tufts)
9 -- altocumulus of a chaotic sky
/ -- middle clouds unobserved due to darkness or obscuration
CH -- High cloud type
0 -- no high clouds
1 -- cirrus fibratus (wispy)
2 -- cirrus spissatus (dense in patches)
3 -- cirrus spissatus cumulogenitus (formed out of anvil)
4 -- cirrus unicus or fibratus (progressively invading sky)
5 -- bands of cirrus or cirrostratus invading sky (less than 45
degree above horizon)
6 -- bands of cirrus or cirrostratus invading sky (more than 45
degree above horizon)
7 -- cirrostratus covering whole sky
8 -- cirrostratus not covering sky but not invading
9 -- cirrocumulus
/ -- high clouds unobserved due to darkness or obscuration
9GGgg -- Time of observation in hours and minutes
Section 2: International Sea Surface Observations
-------------------------------------------------
222Dv 0sTTT 1PPHH 2PPHH 3dddd 4PPHH 5PPHH 6IEER 70HHH 8aTTT
222Dv
D -- direction of ship movement
0 -- calm
1 -- NE
2 -- E
3 -- SE
4 -- S
5 -- SW
6 -- W
7 -- NW
8 -- N
9 -- unknown
v -- ship's average speed
0 -- 0 knots
1 -- 1 to 5 knots
2 -- 6 to 10 knots
3 -- 11 to 15 knots
4 -- 16 to 20 knots
5 -- 21 to 25 knots
6 -- 26 to 30 knots
7 -- 31 to 35 knots
8 -- 36 to 40 knots
9 -- over 40 knots
0sTTT -- Sea surface temperature
s -- sign of temperature (0=positive, 1=negative)
TTT -- Temperature in .1 C
1PPHH -- Wave heights in 0.5 m increments
PP -- Period of waves in seconds
HH -- Height of waves in 0.5 m increments
2PPHH -- Wave period and heights (instrumented)
3dddd -- Direction of swells (up to 2 swells)
4PPHH -- Period and direction of first set of swells
5PPHH -- Period and direction of second set of swells
6IEER -- Ice accretion on ships
70HHH -- Wave heights to 0.1 m (instrumented)
8aTTT -- Wet bulb temperature
Section 3: Special Regional or Climatological Data
--------------------------------------------------
333 0.... 1sTTT 2sTTT 3Ejjj 4Esss 5jjjj jjjjj 6RRRt 7RRRR 8Nchh
9SSss
333
0.... -- Regionally developed data
1sTTT -- Maximum temperature over previous 24 hours
s -- sign of temperature (0=positive, 1=negative)
TTT -- Temperature in .1 C
2sTTT -- Minimum temperature over previous 24 hours
s -- sign of temperature (0=positive, 1=negative)
TTT -- Temperature in .1 C
3Ejjj -- Regionally developed data
4Esss -- Snow depth
E -- State of ground with snow cover
0 -- predominantly covered with ice
1 -- compact or wet snow covering less than half of ground
2 -- compact or wet snow covering more than half of ground but not
completely covered
3 -- even layer of compact or wet snow covering entire ground
4 -- uneven layer of compact or wet snow covering entire ground
5 -- loose dry snow covering less than half of ground
6 -- loose dry snow covering more than half of ground but not
completely covered
7 -- even layer of loose dry snow covering entire ground
8 -- uneven layer of loose dry snow covering entire ground
9 -- snow covering ground completely with deep drifts
sss -- snow depth in cm
5jjjj jjjjj -- Additional information (can be multiple groups)
6RRRt -- Liquid precipitation
RRR -- Precipitation amount in mm
001 -- 1 mm
002 -- 2 mm
...
988 -- 988 mm
989 -- 989 or more mm
990 -- Trace
991 -- 0.1 mm
992 -- 0.2 mm
...
999 -- 0.9 mm
t -- Duration over which precipitation amount measured
1 -- 6 hours
2 -- 12 hours
3 -- 18 hours
4 -- 24 hours
5 -- 1 hour
6 -- 2 hours
7 -- 3 hours
8 -- 9 hours
9 -- 15 hours
/ -- 24 hours
7RRRR -- 24 hour precipitation in mm
8NChh -- Cloud layer data
N -- cloud coverage of layer
C -- genus of cloud
0 -- cirrus (Ci)
1 -- cirrocumulus (Cc)
2 -- cirrostratus (Cs)
3 -- altocumulus (Ac)
4 -- altostratus (As)
5 -- nimbostratus (Ns)
6 -- stratocumulus (Sc)
7 -- stratus (St)
8 -- cumulus (Cu)
9 -- cumulonimbus (Cb)
/ -- cloud not visible
hh -- height of cloud base
00 -- less than 30 m
01 -- 30 m (100 ft)
02 -- 60 m (200 ft)
03 -- 90 m (300 ft)
...
50 -- 1500 m (5000 ft)
56 -- 1800 m (6000 ft)
57 -- 2100 m (7000 ft)
...
80 -- 9000 m (30000 ft)
81 -- 10500 m
82 -- 12000 m
...
88 -- 21000 m
89 -- greater than 21000 m
90 -- 0 to 50 m
91 -- 50 to 100 m
92 -- 100 to 200 m
93 -- 200 to 300 m
94 -- 300 to 600 m
95 -- 600 to 1000 m
96 -- 1000 to 1500 m
97 -- 1500 to 2000 m
98 -- 2000 to 2500 m
99 -- above 2500 m
9SSss -- Supplementary information
333 identifier for section 3
1snTxTxTx 6-hr maximum temperature
2snTnTnTn 6-hr minimum temperature
4E'sss E' is the state of the ground (normally / in the
US) and sss is the depth of snow on the ground, in cm.
7R24R24R24R24 24-hr precipitation amount, in 0.1 mm increments
8NsChshs This group is for the encoding of multiple cloud
layers in terms of the ten basic cloud groups; each cloud group
(identified by the C) may cover up to Ns oktas of the sky and may
have a base encoded in hshs.
9SPSPspsp These are for special phenomena.
Section 4: Not used
----------------------------------------------------
Section 5: Meteorological data for national exchange
----------------------------------------------------
Begins with 555 if present
In the US:
555 [RECORD] [0itDtDtDt] [1snTT snTxTxsnTnTn]
[RECORD] [2R24R24R24R24]
[marine/CMAN stations] 11fff10 22fff20 3GGggvx 4dddffvx
6GGgg dddfff0 dddfff1 dddfff2 dddfff3
dddfff4 dddfff5
[US land stations] 9YYGG is repeated
[] = optional
<top>
Appendix #5: BUOY Code
======================
The header SSVX identifies bulletins of observations coded in FM
18-X.
Note: This code form replaced the former FM 18-IX Ext DRIFTER
code.
Observations from buoys similar to observations from ships are
encoded in the SHIP code, FM 12 or FM 13, and are included in
bulletins headed SMV/, SIV/ etc.
For a full decode please refer to the WMO Manual on Codes, Volume
I.1 Part A: Alphanumeric codes, WMO Publication No 306, available
from: The WMO Secretariat at PO Box 2300, CH-1211 Geneva 2,
Switzerland, price Sw Fr 130.- (February 1998)
The following Sections are only included if there are data
available
SECTION 0 Identification, time and position data
MiMiMjMj A1bwnbnbnb YYMMJ GGggiw QcLaLaLaLaLa
LoLoLoLoLoLo (6QiQt//)
SECTION 1 Meteorological and other non-marine data
(111QdQx 0ddff 1snTTT 2snTdTdTd OR 29UUU 3P0P0P0P0
4PPPP 5appp
SECTION 2 Surface marine data
(222QdQx 0snTwTwTw 1PwaPwaHwaHwa ..... .....
SECTION 3 Temperatures, salinity and current (when available)
at selected depths
333Qd1Qd2 ..... .....
SECTION 4 Information on engineering and technical parameters
including quality control data)
444 (1QpQ2QTwQ4) ..... .....
INTERPRETATION
SECTION 0 (Identification, time and position data)
MiMiMjMj Always coded as ZZYY
A1bwnbnbnb The buoy number or identifier
A1bw The WMO Region and sub-region in which
the buoy was deployed, eg 62 includes
the seas around the UK and to the west
and south-west of the British Isles.
nbnbnb Type and serial number of the buoy (500
is added to the serial number when the
buoy is a drifting buoy)
YYMMJ YY Date
MM Month
J Last digit of the year
GGggiw GGgg Time of the observation
iw Indicator for source and units of wind
speed
0 or 1: Wind speed metres/sec;
3 or 4: Wind speed knots
QcLaLaLaLaLa Qc Quadrant of the globe
N hemisphere: 7 is degrees West, 1 is
degrees East
S hemisphere: 5 is degrees West, 3 is
degrees East
LaLaLaLaLa Latitude (eg 54126 decoded as 54.126
degrees, 54.12/ decoded as 54.12
degrees and 541// as 54.1 degrees)
LoLoLoLoLoLo Longitude (eg 132463 decoded as 132.463
degrees, 05621/decoded as 56.21 degrees,
and 1458// as 145.8 degrees
(6QiQt//) Quality control indicators (see WMO
Manual on Codes)
SECTION 1 (Meteorological and other non-marine data)
111QdQx Quality control indicators for the section
0ddff 0 Indicator
dd Wind direction in tens of degrees
ff Wind speed in knots or m/s
1snTTT 1 Indicator
sn Sign of temperature - 0: positive or zero,
1: negative
TTT Dry-bulb temperature in tenths of a degree
Celsius
2snTdTdTd 2 Indicator
sn Sign of temperature
TdTdTd Dew-point temperature in tenths of a degree
Celsius
OR
29UUU 2 Indicator
9 Relative humidity follows
UUU Relative humidity expressed as a percentage:
first figure zero except when UUU is 100
percent
3P0P0P0P0 3 Indicator
P0P0P0P0 Pressure at station level, in tenths
of a millibar, omitting the thousands
digit
4PPPP 4 Indicator
PPPP Mean sea level pressure, in tenths of a
millibar,
omitting the thousands digit
5appp 5 Indicator
a Characteristic of pressure change
ppp Pressure change over last three hours in
tenths of a millibar
|
