Inflight Advisories
Inflight Advisories is a core knowledge area on the Aviation Weather FAA written exam. This hub collects our 6 in-depth, ACS-aligned inflight advisories articles — each written in plain English and grounded in the official FAA handbooks. Work through them below, then drill the topic with practice questions.
Center Weather Advisories (CWA) and the CWSU Role
Center Weather Advisories (CWAs) are short-fuse, unscheduled inflight advisories issued by Center Weather Service Units (CWSUs) to alert pilots and ATC to significant meteorological conditions affecting en route and terminal operations within the next two hours.
Convective SIGMETs: Thunderstorm Lines, Embedded Cells, and Hail
Convective SIGMETs warn pilots of the most dangerous thunderstorm-related hazards in the CONUS, automatically implying severe turbulence, severe icing, and low-level wind shear for every issuance.
SIGMETs Explained: Non-Convective Hazards and Issuance Criteria
SIGMETs are urgent inflight advisories issued for en route weather hazards that threaten flight safety; non-convective SIGMETs cover severe turbulence, severe icing, volcanic ash, and widespread dust or sandstorms, and are valid for up to four hours.
AIRMETs Sierra, Tango, and Zulu: Decoding the Graphical G-AIRMET
AIRMETs Sierra, Tango, and Zulu warn pilots of IFR conditions, turbulence, and icing respectively; the graphical G-AIRMET over the CONUS provides higher-resolution hazard snapshots every three hours up to 12 hours into the future.
Volcanic Ash Advisories and the VAAC Network
Volcanic Ash Advisories (VAAs) are critical safety products issued by the global VAAC network that warn pilots and dispatchers about ash clouds from erupting volcanoes — clouds that can catastrophically damage jet engines and erode flight-critical surfaces.
Tropical Cyclone and Space Weather Advisories Decoded
Tropical cyclone and space weather advisories appear inside Convective SIGMETs and non-CONUS SIGMETs with unique valid periods and decoding rules every instrument pilot must master before departure.
More Aviation Weather subjects
Articles are original summaries grounded in the public-domain FAA handbooks and cite their source. ACS-aligned study aids — not a substitute for the official handbooks or regulations.