Meteograms

What are Meteograms?

Meteograms show the forecast weather for one place using a horizontal timeline with various weather elements placed vertically. They are useful for seeing changes in weather through the day (e.g. how much rain is happening at different times) as well as seeing how the different weather elements change in sympathy with one another (e.g. a cold change brings a temperature drop, rain and strong winds).

A question you should always ask before accepting the forecasts in a meteogram is how they were produced. Most meteograms are the simple computer output from one model, sometimes assisted by proprietary additions that are not disclosed. The best meteograms are from a combination of models with the constant input of human forecasters. The notes for each meteogram give information on this.

Be careful not to confuse precision with accuracy - a forecast for 15 days from now may say "Sunny, maximum 21 degrees" which is very precise, but it may be completely wrong. All forecasts degrade the further into the future they are made, and with current science and technology forecasts are likely to be good up to 4 days, fair between 5 and 7 days, and poor beyond 7 days regardless of who is making them.

Bureau of Meteorology

MetEye

The meteograms in MetEye are constructed by Bureau forecasters using numerous computer models and tools to manually adjust the forecasts for local conditions. They are in tables rather than graphs, extend out to 6 or 7 days and are updated at least twice daily, around 6am and pm. To get to a meteogram, click the link at left, select your location using the Change location box, then click Detailed 3-hourly forecast in the top right corner. 25/7/14

Weatherzone

Meteograms for paid subscribers only

Weatherzone's meteograms are based solely on the output from computer models, with three currently available: the Bureau's ACCESS-G (global) and ACCESS-R (regional), and the US GFS model. They provide graphs for numerous elements at different levels in the atmosphere. 25/7/14

Norwegian Meteorological Institute (met.no)

www.yr.no

This site is useful because it gives forecasts from the respected European ECMWF model with further processing by met.no. It also gives them for over 8 million places in the world. In the menu, Hour by hour gives a graph and table for the next two days while Long term goes in less detail out to 9 days. 25/7/14

WeatherSpark

WeatherSpark

This is a more complex version of yr.no, and you can choose between forecasts from met.no (i.e. yr.no), which are based on the ECMWF, or World Weather Online, which uses its own proprietary systems. A clean forecast graph shows as many elements as you could wish for any location you type into the search box. Use the first button below the word forecast in the top right corner to select met.no or WWO forecasts. Use the Graphs button below it to select what appears on the graph (try ticking Show all to see what's available. A comprehensive help page is essential reading, and remember there is a lot more available for users in the USA than Australia. A word of warning: the historical and averages information for Australia is taken from a very thin selection of stations - those for Bathurst NSW come from Richmond near Sydney and those for Charleville QLD come from Rockhampton, over 500km away. Check the thick black line on the map which shows the location you entered at one end and the location used for history and averages at the other. 28/7/14

Ogimet

Gramet meteo

This is an industrial-strength meteogram that needs some work on your part to understand, after which it is enormously useful for those really interested in the weather. It shows vertical cross-sections through the atmosphere, either above one location over time, or between two or more locations at the one time or over time. The cross sections show cloud, wind, temperature and precipitation while a table gives actual readings at a nominated elevation (typically the surface). Detailed help is here. For the location(s) it is easiest to use World Meteorological Organisation (WMO) index numbers. Click Query about indexes here or on the left-hand menu, enter the location name in the Common name box, click Send, then note the WMO index number of the appropriate location. If you don't get a result, try another nearby large city or town. An important point: the maximum duration you can ask for is 96 hours; ask for more and you get an error message (in Spanish). 25/7/14