There are three types of AIRMET, all identified by a phonetic letter: S (Sierra), T (Tango), and Z (Zulu).
AIRMET SIERRA (Mountain Obscuration or IFR) ceilings less than 1000 feet and/or visibility less than 3 miles affecting over 50% of the area at one time. Extensive mountain obscuration.
AIRMET TANGO (Turbulence) Moderate Turbulence, sustained surface winds of 30 knots or more.
AIRMET ZULU (Icing) Moderate icing, freezing levels
In order for an airmet to be issued, the applicable conditions must be widespread. By definition, "widespread" means that the applicable area covers at least 3000 square miles. Because conditions across the forecast period can move across the area, it is possible that only a small portion of the area is affected at any given time.
AIRMET’s are routinely issued for 6 hour periods beginning at 0145Z during Central Daylight Time and at 0245Z during Central Standard Time. AIRMETS are also amended as necessary due to changing weather conditions or issuance/cancellation of a SIGMET.
Airmets get graphic: tired of Airmets for icing the size of Montana? some relief is coming from the official weather channels.(WX SMARTS)(airmen's meteorological information)(Report)
Nov 01, 2008; Text-based forecasts made logical sense 20 or more years ago, when teletype and facsimile were the primary method of transmitting...
The end of AIRMETS: AIRMETs and Area Forecasts are going the way of the A-N radio range, and their replacements don't require No-Doz to use.(WX SMARTS)(Airmen's Meteorological Advisory)
Jan 01, 2006; Ever feel guilty that you don't read every line of the Area Forecast (FA) for your route? Fly in the clouds without guilt this...