What is required to be issued when severe icing conditions NOT associated with thunderstorms are occurring?

• A. SIGMET
• B. PIREP
• C. AIRMET
• D. SPECI

Answer: (A)

Severe icing not associated with thunderstorms is a significant weather hazard that en route air traffic controllers and pilots need to be warned about across a region, so it’s conveyed with a SIGMET. SIGMETs are issued for non-convective phenomena that could affect the safety of all aircraft, and they alert pilots to potentially hazardous icing conditions over a aangegeven area for several hours. By contrast, an AIRMET covers lighter to moderate icing and typically applies to smaller areas or lower altitudes, so it wouldn’t be issued for severe icing. PIREPs are pilot reports of observed conditions and do not serve as formal warnings, and SPECI is a special METAR update for rapid surface changes rather than a route-wide warning product.