AIRMET (Airmen’s Meteorological Advisory)
An AIRMET (Airmen’s Meteorological Advisory) is a weather advisory issued when conditions of operational concern to light aircraft exist or are forecast and were not already adequately depicted in the current Graphical Forecast for Aviation (GFA).
AIRMET Criteria in Canada
- Moderate icing
- Moderate turbulence
- Sustained surface winds of 30 knots or more
- Ceilings below 1,000 ft AGL and/or visibility below 3 SM affecting more than 50% of the area
- Extensive mountain obscurement
AIRMET vs. SIGMET
AIRMETs cover conditions significant but less severe than SIGMET criteria. SIGMETs are issued for severe or extreme conditions (severe turbulence, severe icing, volcanic ash, tropical cyclones) hazardous to all aircraft. If you see a SIGMET in your weather picture, treat it with serious respect regardless of aircraft type.
On the TC Written Exam
Know the distinction: AIRMET targets light aircraft, moderate conditions; SIGMET is for severe conditions affecting all aircraft. Both must be checked during pre-flight weather briefing.