What is the purpose of SIGMETs in planning routes?

• A. To warn of significant weather hazards including severe convection; use to route around storms or delay.
• B. To provide engine performance guidelines
• C. To instruct pilots to file a flight plan
• D. To indicate air traffic frequency changes

Answer: (D)

SIGMETs warn about significant weather hazards that can affect flight safety, such as severe thunderstorms, embedded convection, strong turbulence, icing, dust storms, or volcanic ash. When planning routes, pilots use these advisories to decide where to fly around the hazard or to delay departures if the affected area overlaps the intended path. The SIGMETs provide details on the hazard, its location, estimated movement, intensity, and time frame, which helps you make strategic route adjustments and timing decisions to minimize exposure. They aren’t about engine performance guidelines, they don’t instruct you to file a flight plan, and they don’t indicate changes in air‑to‑air or air‑to‑ground frequencies. The purpose is to alert you to weather dangers so routes can be planned to stay clear and safe.