What is a SIGMET intended to report on?

A SIGMET, or Significant Meteorological Information, is specifically designed to provide information on hazardous weather conditions that can affect the safety of air traffic. The correct choice focuses on severe weather phenomena such as severe icing, turbulence, and volcanic ash.

Severe icing can create dangerous flying conditions, especially for aircraft that are not equipped to handle it. Likewise, severe turbulence can pose significant risks during flight, including passenger injuries and structural stress on the aircraft. The presence of volcanic ash also represents a serious hazard, as it can severely damage aircraft engines and impact visibility.

The intent of a SIGMET is to alert pilots and air traffic control to these severe conditions, allowing for appropriate decisions regarding flight safety and route adjustments. This information is vital for pilots to ensure they can navigate through or around these hazardous areas, enhancing overall aviation safety.

Other weather phenomena such as moderate turbulence or mountain obscuration are not classified as significant enough to warrant a SIGMET, which differentiates it from other types of advisories and reports in aviation weather services.