What natural phenomenon may lead to the issuance of SIGMETs?

The issuance of SIGMETs, or Significant Meteorological Information, is specifically related to hazardous weather phenomena that could impact safety in aviation. Areas of active thunderstorms are a primary concern because they can produce severe turbulence, wind shear, hail, and icing conditions that pose significant risks to aircraft in flight.

Thunderstorms can develop rapidly, bringing with them intense weather that can affect flight operations. For this reason, when meteorologists identify areas of active thunderstorms, they issue SIGMETs to alert pilots and air traffic controllers about the potential hazards in those regions. This allows for better planning and management of flights to avoid dangerous weather conditions.

In contrast, clear weather, calm winds, and a stable atmosphere are associated with safe flying conditions and do not typically warrant a SIGMET, as these conditions pose little or no risk to aviation. Thus, the focus on active thunderstorms as a trigger for SIGMET issuance underscores their potential to significantly impact flight safety.