Note that all times are the clock
time in force in the relevant state or territory
Go here for information on how to save the Daily Weather Summary on
your computer.
The National Daily Weather Summary summarises significant,
unusual and noteworthy weather around Australia on a day-by-day
basis. While the format has evolved, AWN has been providing a daily
summary since it began in 1996 -- archives are available off the Daily
Weather Summary index pages.
While the graphics and statistical information is updated
automatically, the Weather Events section
is written in my spare time so,
unfortunately,
doesn't
always
get updated to a strict schedule and there are gaps at times
that I am busy.
Graphics: These are sourced from the Bureau of Meteorology.
Until they become available, text in their space will indicate approximately when to expect them. Click on the charts or the links under them
to open full-sized versions. These open in separate windows, allowing
you to click between them to make comparisons.
Statistics: It takes until the afternoon of the
following day for all the information to become available. I source this information
from synoptic and automatic weather station reports from the Bureau,
but it is also supplemented with daily downloads of information from
the Bureau's National Climate Centre. Some important points to note:
- Records set today: As soon as data is received, it is compared against my database of extreme temperatures, rainfall and wind for each location. If it appears to be a record, it is immediately listed. As my database is not as up to date as the Bureau of Meteorology's, I check the Records set today section against the latest BoM data after all information has come in, and indicate it's been checked in the header. This section is more complex than it looks and has its own help page here.
- Minimum and grass (or ground or terrestrial) minimum readings are for the
24 hours to 9am and are initially received to the whole degree. These
are replaced with more accurate readings later in the day.
- Maximum temperatures are for the 24 hours FROM 9am.
Observers report an interim maximum to 3pm, but this is replaced
with the official more accurate figure later the next day. It frequently gets hotter after 3pm local
time (especially when daylight savings time is in force), so the
interim figures are often revised upwards.
- Rainfall, evaporation and wind run are recorded for
the 24 hours to 9am and are available same day.
- Maximum wind gust and sunshine are recorded for
the 24 hours midnight to midnight, and are available later the next day.
- Wind run is measured by a cup anemometer and represents
the length of air passing the station over 24 hours. Divide by 24
to get an average speed.
- Downpours are measurements of short-term heavy
rainfall (periods of 6 hours down to 1 minute). These are calculated
from AWS routine and special reports and 3-hourly synoptic reports.
The criteria for inclusion vary depending on the duration reported;
for example, durations of less than 5 minutes are reported if the
rainfall rate exceeds 80mm/hour while durations of 3 hours are reported
if rainfall rate exceeds 5mm/hour. There is inevitably some duplication
within time periods, but this helps to define the timing of the heavy
rain. While AWSs are programmed to send special reports during heavy
rain, this list is not an exhaustive one.
- Highest gusts and Gales and gusts seem
to be reporting the same thing, but there are a few differences. Highest
gusts are the official maximum wind gust reported for the
24 hours midnight to midnight. At manual observing stations, such
as airports, a Dines Anemograph is used providing an extremely accurate
measurement that the observer reads off a chart. At AWSs, the maximum
gust is recorded by a cup anemometer. Gales and gusts are
reported from routine and special reports received from AWSs through
the day. Note that two measures are given, the gust speed, usually
measured over a few seconds, and the average or sustained speed,
which is usually the average over
a 10-minute
period. Variations between the reported maximum gust in the two parts
of the Daily Weather Summary can happen for a variety of reasons.
The top gust may not have been reported in the routine or special
reports through
the
day,
but is picked up in the whole-of-day statistics. Or the top gust
reported in real time through the day from an airport may have been
measured by a cup anemometer while the whole-of-day reading is from
a Dines.
- Late rainfall reports. Australia is fortunate
in having thousands of voluntary rainfall observers that read gauges
at 9am daily, record the rainfall on a form and post the form off
the the Bureau at the end of the month. This data is entered national climate database (ADAM, short for Australian Data Archive for Meteorology) and becomes available some time afterwards. While about
2000 rainfall observations are reported daily to the Bureau, another
6000 or so come later by post. Rainfall is the meteorological element
that is most variable over space and time, and vital for primary producers, so these additional reports
add immensely to the weather record. I re-run the program that produces
the Daily Weather Summary several months after each day to pick up
these late reports -- check the date of the latest run at the top
of the statistical section.
- Quality control. This is explained in more detail here.
Weather events: I write brief accounts of both Australian and international weather events at the top of the relevant Daily Weather Summary. These are repeated on the AWN homepage. A few points to note:
- AWN is a spare-time activity of one individual. There will be gaps
in the record. Some events will produce a sizable story
while equivalent events at another time
will just get a few lines. I would love to
consistently and accurately report all events, but time doesn't always
allow that.
- Stories tend to be written a day or more after the event. I find
that it takes that long for sufficient accurate information to become
available and for facts to be verified.
For weather
news as it
happens, try the AWN page of links to reliable media sources.
- Sometimes, I will incorporate additional
or corrected information that I become aware of well after an event. These stories are
marked as updated in the headline.
- I frequently add links
to more detailed reports of events on other sites if I am aware
of them.
If you want to save the Daily Weather Summary
to your computer:
Each Daily Weather Summary is made up of a many separate files, all linked together by one controlling file. In most browsers, if you simply save the file using the default setting, you'll get the controlling file plus all the separate bits placed in a special folder linked to the controlling file. If you save many DWSs, you can end up with a lot of large folders.
There are two more satisfactory options. The following apply to the Chrome browser. For other browsers, Google "save a web page as a single file in [your browser name]".
Save as a pdf. This is easiest, but doesn't give the better results.
- With the DWS page on screen, right-click in a blank area and select Print (or just Ctrl+P for Windows, Command+P for Mac).
- At the top left in the screen that comes up, you will probably see a Print button and the name of your printer underneath. Click the Change button and select Save as PDF from the list.
- You now have a Save instead of a Print button. Click it, select where you want to save the file and click Save.
Save as a mhtml file. This saves the page you see as a single file that includes all its components, including images, and is identical to what you see on the screen. Most browsers can read mhtml files. Although Chrome has had the ability to save files in mhtml for years, for some reason you have to enable it before starting. The little-used but excellent Opera browser has it as standard. Here's how to set it up in Chrome:
- In the Chrome address bar, type chrome://flags. This brings up the Experiments page along with some dire warnings. I've never had any problems with the mhtml "experiment".
- It's a long page so search (Ctrl+F for Windows, Command+F for Mac) for mhtml.
- This takes you down to Save page as MHTML. Enable it.
- Finally, click the Relaunch now button to relaunch Chrome.
Once you've set mhtml saving up, saving a DWS page, or any page as a single file is easy:
- Right-click in any blank area and select Save as (or just Ctrl+S, Command+S on Mac)
- In the Save as window, choose Webpage, Single File under Save as type, select where you want to save the file, and click Save.
(26/09/18) |