A few habits of this list are worth knowing before you drill it. Several single letters carry more than one meaning depending on where they appear in a report: E is east, ended, or an estimated ceiling; S is snow or south; SW is a snow shower or southwest; R is right or runway; IC is ice crystals or in-cloud lightning. Two codes share one meaning: V and VRB both read variable. And in the body of a report, weather-group intensity is carried by the bare symbols — - for light, + for heavy, and no prefix at all for moderate — while descriptors and phenomena chain into single groups: -FZDZ is light freezing drizzle, BLSN is blowing snow. That chaining is what the Decode a METAR drill practices.
About this list
The list gathers every abbreviation and acronym used across the METAR/TAF decode key — not just the codes that appear inside a raw observation. Report codes like BKN, RA and VRB sit alongside remark-section markers (AO2, PRESFR, SNINCR), sensor-status flags (PNO, FZRANO, VISNO), runway and visibility terms (RVR, DVR), and the agencies and handbooks behind the format (NWS, ICAO, FMH-1). If a code ever shows up in a report, its remarks, or the paperwork around them, it is here.
The governing document for METAR coding in the United States is Federal Meteorological Handbook No. 1, Surface Weather Observations and Reports (FMH-1); the decode key condenses it to one card. Entries are transcribed exactly as printed, including the key's own quirks — KT is expanded as KNOTS, cd, max and min run lowercase, and AO1/AO2 sit slightly out of alphabetical order. The one departure: the card prints HLSTO's code twice; it appears once here.
Transcribed from “METAR/TAF List of Abbreviations and Acronyms,” FAA METAR/TAF weather conversion card (alaska.faa.gov, metcont.htm, retrieved December 24, 2008). The same key circulates as the NWS Western Region METAR decode packet.