AWH 3-19

Chapter 3, Overview of Aviation Weather Information 3-19 Precipitation Information Contained In: Type Summary Advisories AIRMET G AIRMETs are issued when weather phenomena such as precipitation restricts visibility (less than 3 SM). CWA T, G May be issued for heavy, extreme, or frozen precipitation. AWW T Intended for ground operations at select airports. Criteria may vary depending on user needs. Examples of criteria that could issue this warning are heavy snow or freezing rain. Forecasts TAF T, G Included when conditions are expected and indicated by various descriptors based on the type of precipitation. Intensity is also coded with precipitation types. Aviation Surface Forecast G Derived from the GFA and includes forecasts of precipitation at specified valid times includes weather phenomena. Alaska Area Forecast T A description of significant clouds and weather, including precipitation. Hawaii Area Forecast T A description of significant clouds and weather, including precipitation. Gulf of America and Caribbean Area Forecast T A description of significant clouds and weather, including precipitation. Alaska Surface Chart G Includes forecast of precipitation. Surface Prog Charts G Depicts the type of precipitation and the forecast percent probability of measurable precipitation. AFD T Describes the weather conditions as they relate to a specific TAF or group of TAFs, including precipitation. MIS T A nontechnical discussion of meteorological events (including precipitation) causing or expecting to impact the flow of air traffic across an ARTCC. Tools GFA Tool G Interactive website that includes precipitation information and overlay of radar. Flight Service Interactive Map G Interactive website that includes overlay of radar.