What is a SIGMET?

• A. A weather advisory issued for a single region's weather.
• B. A SIGMET is a significant weather advisory for all aircraft; it indicates severe weather such as thunderstorms or intense turbulence affecting safety.
• C. A forecast for icing only.
• D. A general aviation update issued daily.

Answer: (B)

A SIGMET signals weather that could threaten flight safety for all aircraft. It’s issued when there’s significant weather phenomena—such as severe thunderstorms or intense turbulence—that could affect safety anywhere in the affected airspace. This advisory is not limited to a single region or to a specific type of aircraft; it’s meant for all aircraft operating in the area. It’s different from icing forecasts or routine daily updates, which are covered by other products. So the description that a SIGMET is a significant weather advisory for all aircraft indicating severe weather like thunderstorms or intense turbulence best captures its purpose and scope.