AWH 3-28

Chapter 3, Overview of Aviation Weather Information 3-28 Flight Categories and color codes serve as a means to help pilots visually assess ceilings and visibilities on a map of METARs. Most aviation weather websites use the following color codes and definitions for their display of METARs/SPECIs (and sometimes TAFs) on their website: • Purple: LIFR = Low IFR, ceilings less than 500 ft and/or visibilities less than 1 SM. • Red: IFR = Ceiling 500 ft to less than 1,000 ft and/or visibility 1 SM to less than 3 SM. • Blue: MVFR = Ceiling 1,000 to 3,000 ft and/or visibility 3 to 5 SM. • Green: VFR = Ceiling greater than 3,000 ft and visibility greater than 5 SM. Note: The VFR Weather Flight Category is not to be confused with the basic VFR weather minimums given in 14 CFR § 91.155. Weather Flight Categories are only intended for situational awareness. Table 3-17. Weather Element: Surface IFR Type: text (T), graphic (G), image (I), voice (V) Surface IFR Information Contained In: Type Summary Observations METAR and SPECI (ASOS, AWOS, ATIS) T, G, V Ceiling less than 1,000 ft and/or visibility less than 3 SM. Note: Websites may graphically depict METAR/SPECI as IFR when ceilings are from 500 ft to less than 1,000 ft and/or visibility 1 SM to less than 3 SM. Analysis Advisories AIRMET T, G AIRMET Sierra is issued when surface-based IFR conditions are occurring or expected to occur. CWA T, G May be issued if conditions are at or approaching LIFR conditions (ceilings less than 500 ft and/or visibilities less than 1 SM). Forecasts TAF T, G Ceiling less than 1,000 ft and/or visibility less than 3 SM. Note: Websites may graphically depict TAFs as IFR when ceilings are from 500 ft to less than 1,000 ft and/or visibility 1 SM to less than 3 SM. Aviation Surface Forecast G Derived from NOAA’s GFA and includes forecasts of surface IFR at specified valid times. Alaska Area Forecast T A 12- to 18-hour categorical outlook for IFR is included in the description of significant clouds and weather. Hawaii Area Forecast T A 12- to 18-hour categorical outlook for IFR is included in the description of significant clouds and weather. Gulf of America and Caribbean Area Forecast T A 12- to 24-hour categorical outlook for IFR is included in the description of significant clouds and weather. Low-Level SIGWX G Areas of forecast IFR conditions are depicted. Alaska SIGWX G Areas of forecast IFR conditions are depicted. AFD T Describes weather conditions such as surface IFR as they relate to the TAF and provide additional aviation weather-related issues.