Definition
An unscheduled in-flight weather advisory issued by a Center Weather Service Unit meteorologist to alert pilots of existing or anticipated adverse weather conditions within the next two hours. A CWA may modify or update an existing SIGMET, AIRMET, or convective SIGMET, or it may warn of conditions that do not yet meet those thresholds but are still hazardous to flight.
Plain English
A short-notice weather warning from the air traffic control center's own weather team, telling pilots about bad weather happening now or expected within the next couple of hours.
Context Anchor
Seen in aviation weather briefings, flight planning tools, and in-flight weather information from air traffic control.
Derivation
Center refers to an Air Route Traffic Control Center (ARTCC), which handles aircraft en route between airports. Weather Advisory means a notice about hazardous weather. So a CWA is a weather notice issued by the Center handling your flight.
Why Pilots Care
CWAs give pilots advance notice of weather hazards such as thunderstorms, severe turbulence, or icing so they can reroute or delay to maintain safety.
Intuition Check
A CWA is not a broad, long-range forecast. It is a short-term advisory for weather affecting a specific FAA center’s area.
Example Sentence 1
Center issued a CWA for moderate to severe turbulence below 12,000 feet, so we requested a higher altitude to get above it.
Example Sentence 2
I reviewed the latest CWAs on the briefing before filing the IFR flight plan.