AWH 3-21

Chapter 3, Overview of Aviation Weather Information 3-21 Fog Information Contained In: Type Summary MIS T A discussion of meteorological events (including fog/mist) causing or expecting to impact the flow of air traffic across an ARTCC. Tools GFA Tool G Interactive website that includes fog/mist. Also includes AIRMET Sierra. Flight Service Interactive Map G Interactive website that includes overlay of AIRMET Sierra. 3.4.2.7 Products with In-Flight Icing Information Table 3-10. Weather Element: In-Flight Icing Type: text (T), graphic (G), image (I), voice (V) In-Flight Icing Information Contained In: Type Summary Observations PIREP/AIREP T, G, V Icing intensity, type, and altitude reported. Noted as an Urgent PIREP or Special AIREP when severe. Analysis CIP G Computer model’s 0-hour forecast (referred to on the product as an analysis) depicting five icing analysis products: - Icing Probability. - Icing Severity. - Icing Severity – Probability > 25%. - Icing Severity – Probability > 50%. - Icing Severity plus SLD. Advisories Convective SIGMET T, G Possible severe icing is implied within the convective SIGMET area. SIGMET T, G Non-convective SIGMETs are issued for severe icing. AIRMET T, G AIRMET Zulu depicts areas of active or expected moderate icing. CWA T, G May be issued for moderate or greater icing. Forecasts Aviation Clouds Forecast G Includes a depiction of icing AIRMETs. Alaska Area Forecast T May includes a description of icing not meeting AIRMET criteria otherwise “NIL SIG” is noted if no significant icing is forecast. Gulf of America and Caribbean Area Forecast T A description of moderate or severe icing conditions. Medium-Level SIGWX G Areas moderate or severe icing are depicted. WAFS G Global icing forecasts provided in a grid point format.