What conditions does SIGMET report?

SIGMET, or Significant Meteorological Information, is designed to convey information about severe weather conditions that can impact flight safety, particularly for aircraft in flight. These reports provide updates on conditions that are significant enough to affect operations, including severe turbulence, thunderstorms, icing, and volcanic ash.

The focus of SIGMET is on hazards that are beyond routine weather phenomena, making option C the correct one as it encompasses severe turbulence and volcanic ash—two critical and potentially hazardous conditions for flying operations. Severe turbulence can lead to loss of control or structural damage, while volcanic ash poses risks to engines and visibility.

Normal weather, minor turbulence, and clear skies, on the other hand, do not necessitate a SIGMET, as they do not represent significant dangers to aircraft operations. Ultimately, SIGMETs are crucial for pilot awareness and safety measures, ensuring that those in flight are informed of serious and immediate weather-related threats.