What does a Convective SIGMET primarily indicate?

A Convective SIGMET (Significant Meteorological Information) is primarily issued to indicate the presence of hazardous convective weather phenomena, primarily focusing on thunderstorm activity. These SIGMETs are crucial for pilots and air traffic controllers as they convey important information regarding severe thunderstorms that could impact flight safety.

When a Convective SIGMET is issued, it signifies that thunderstorms are likely to produce severe turbulence, severe icing, or wind gusts of 50 knots or greater, along with hail of 3/4 inch in diameter or larger. The focus is specifically on the convective phenomena associated with thunderstorms, making operational decisions based on the potential dangers these storms pose to aviation.

The other options pertain to different weather phenomena. While extreme wind shear and severe icing conditions can be associated with thunderstorms, they are not the primary indicators for the issuance of a Convective SIGMET. Visibility issues due to fog do not relate to convective activity and are covered under different advisories in aviation meteorology, making them unrelated to the focus of a Convective SIGMET.