Which weather product is used to describe weather hazards over a region that may affect flight operations outside of a specific airport area?

• A. AIRMET
• B. MIS
• C. SIGMET
• D. WST

Answer: (C)

SIGMETs communicate significant weather hazards that can affect flight operations across a region, not limited to a single airport. They warn about phenomena that pose a hazard to all aircraft and can impact routing and en-route decisions, such as severe turbulence, severe icing, dust or sand storms, volcanic ash, and line or embedded thunderstorms. They cover a defined geographic area and are valid for several hours (convective SIGMETs for thunderstorms have shorter validity). This regional scope is why SIGMET is the best choice when the concern is hazards that could affect operations outside of a specific airport area. AIRMETs describe less severe conditions for smaller aircraft, and the other options aren’t the regional, significant-hazard product used for this purpose.