Why aren GFAs and SIGMETs available in plain language?
It is because these bulletins are already written in abbreviated English. If you have problems with the abbreviations used in those bulletins, click on the Publication tab (top right of the banner) then scroll down and click on “links for non-kiosk users”, click the MANAB hyperlink. MANAB is the manual of abbreviations used by forecasters. International SIGMETs observe the full ICAO (International Civil Aviation Organization) format, which means that the text they contain is written out in full English, i.e. no abbreviations are used.