What type of weather advisory is valid for 4 hours and covers non-convective hazards?

The correct answer is AIRMET. An AIRMET is specifically designed to provide information about non-convective weather hazards that are significant to the safety of pilots. These advisories typically cover a time frame of 4 hours and can include conditions such as turbulence, icing, or low visibility due to weather that is not associated with convective activity.

In contrast, other types of advisories such as SIGMETs cover more severe weather phenomena, including convective activity like thunderstorms. A TAF (Terminal Aerodrome Forecast) provides a forecast for a specific airport area and typically has a longer time frame, while METARs are aviation routine weather reports that give current weather conditions, not advisories for upcoming hazards. Thus, the AIRMET is uniquely suited for addressing non-convective hazards over a 4-hour period.