Definition
A National Weather Service field office responsible for preparing and issuing aviation and public weather forecasts for a defined geographic area. WSFOs historically produced terminal forecasts, area forecasts, and other aviation weather products used in flight planning.
Plain English
A National Weather Service office that writes and issues weather forecasts, including the ones pilots use to plan flights.
Context Anchor
Seen in FAA abbreviation lists and weather-related aviation material when identifying the office connected with a forecast or weather warning.
Derivation
Straightforward initials: Weather Service Forecast Office. 'Forecast' comes from Old English fore- (before) and cast (to throw or plan), meaning to plan or estimate ahead — which is exactly what these offices do for the atmosphere.
Why Pilots Care
The forecasts pilots rely on for preflight planning — winds aloft, area forecasts, terminal forecasts — originate from National Weather Service offices like WSFOs. Knowing where the products come from helps pilots understand their scope and limitations.
Example Sentence 1
The area forecast for the cross-country leg was issued by the regional WSFO earlier that morning.
Example Sentence 2
WSFO products are referenced during preflight weather briefings for route planning.