What weather conditions warrant the issuance of an AIRMET?

An AIRMET, or Airmen's Meteorological Information report, is specifically designed to inform pilots about weather conditions that may be hazardous to light aircraft and Visual Flight Rules (VFR) operations. This includes a range of weather phenomena that could impair flight safety, typically affecting smaller aircraft at lower altitudes.

The primary purpose of an AIRMET is to alert pilots about conditions such as moderate turbulence, sustained surface winds of 30 knots or more, widespread areas of ceilings below 1,000 feet, or visibility below 3 miles. The focus is on ensuring the safety of light aircraft and VFR pilots, as they often operate in less severe conditions compared to larger commercial aircraft.

In contrast, the scenario involving severe thunderstorms is typically covered by a different advisory, such as a Severe Weather Watch or a Convective SIGMET, which indicates more urgent and hazardous conditions likely to affect larger aircraft. Similarly, extreme turbulence may warrant a different type of report focused on that specific hazard, while low visibility due to fog, although critical, would not always meet the criteria for an AIRMET unless it significantly affects VFR operations over a broad area.