Definition
A former National Weather Service unit responsible for issuing in-flight aviation weather advisories — principally AIRMETs, SIGMETs, and Convective SIGMETs — for the contiguous United States. Its functions have since been absorbed by the Aviation Weather Center (AWC) in Kansas City, Missouri.
Plain English
A government weather office that used to write the urgent in-flight weather warnings pilots rely on, like advisories about turbulence, icing, and thunderstorms. Its job is now done by the Aviation Weather Center.
Context Anchor
Seen in FAA acronym lists and in older aviation weather references.
Derivation
Plain expansion of the initials: National (covering the whole country), Aviation Weather (weather information specifically for flying), Advisory Unit (the office that issues advisories — short notices warning pilots of hazardous conditions).
Why Pilots Care
Pilots may still see NAWAU referenced in older training material or legacy documents. Recognizing it as the predecessor to the Aviation Weather Center helps when reading historical references to AIRMETs and SIGMETs.
Intuition Check
Do not read “National Aviation Weather Advisory Unit” as a local weather desk. It refers to a national-level aviation weather office.
Example Sentence 1
Older textbooks credit NAWAU with issuing AIRMETs and SIGMETs, though that responsibility now belongs to the Aviation Weather Center.
Example Sentence 2
NAWAU advisories helped identify areas of turbulence along the route.