What does the acronym SIGMET stand for?

The acronym SIGMET stands for "Significant Meteorological Event." It refers to a type of advisory issued by meteorological authorities to provide updates on significant weather events that can impact safety for aircraft operations. These events include phenomena such as severe turbulence, thunderstorms, volcanic ash clouds, and other hazardous conditions that may affect flight safety. Air traffic controllers and pilots rely on SIGMETs to make informed decisions while in-flight or planning routes, ensuring they have the most current and relevant meteorological information.

The other options describe terms or concepts that do not correctly reflect the purpose of a SIGMET. For instance, while "Special Meteorological Information" sounds similar, it does not accurately convey the significance or type of events that SIGMETs cover.