It’s not bad enough that aviation is replete with endless acronyms, but the powers that be have also created a convoluted collection of contractions culled to confuse. Moreover, several abbreviations are derived from French, not English. Thanks France!
The first reaction many people have is ‘”Why?” It was mine as well, especially since more than forty years have passed since the teletype was already on its way out. Data transmission today is far more robust and dirt cheap, so why would this trend continue? The short answer is that if one were to convert those acronyms to a standard English paragraph it can become voluminous. Especially if you look at an example D-ATIS transmission from a small class ‘C’ airport:
In English, the D-ATIS example above becomes, “Reno Tahoe ATIS information Alpha, two two five five Zulu. Winds two five zero at one two, gusts two three. Visibility one zero. Seven thousand scattered, two five thousand scattered. Temperature one two, dewpoint minus four. Visual approach in use. Landing and departing runway three four left, three four right, two five. Approaches to parallel runways in use. Ensure correct runway alignment. Notice to air missions, five ‘G’ NOTAMS in effect. Contact flight services for more information. Hazardous weather information for Nevada, California available from flight services. Low level wind shear advisories in effect. Moderate turbulence reported below twelve thousand. Advise on initial contact you have information Alpha.“
While the complaints continue and debate rages about how to make changes it is still a ‘language’ we will need to understand at least in limited fashion – whether we like it or not. It is also something every pilot is tested on, so some level of proficiency will be required.
The upside to this is that as these TAFs and METARs are more frequently encountered they gradually become easier to read and it becomes possible to see and understand a good amount of weather information in just a glance.
The Aeronautical Information Manual has a figure in section 7-1 which is a key to decode many common ASOS/AWOS codes.
However, in your travels you will likely encounter many codes not included in what the AIM has to offer. A discontinued, but still very valuable resource that I have available for download, is a pamphlet the Air Force put together called the “Aircrew Quick Reference to the METAR and TAF Codes“.
There are online METAR and TAF decoders as well. If you have the text of a METAR you want to decode you can copy the text string and paste it into this site for a translation. The site also has the ability to look up and decode many airports by searching via their ICAO code.
If you are interested in historical METARs and TAFs for an airport, say during a major storm, you can use this site to look into their archive and test your own decoding ability. If you get stumped you can then copy and paste it into the decode site above.
Last, but not least. For a little uncensored levity to break away from the seriousness of severe weather, you can visit this YouTube creator’s website which takes a real airport METAR and has a little (okay, a lot of) fun in the translation. He even has a mobile version, so you can take the fun with you. Enjoy!