Definition
A network of weather observing stations, often staffed by trained non-government observers at smaller airports, that takes and reports surface weather observations to supplement the primary network of automated and government-staffed stations. SAWRS observations feed into the standard aviation weather distribution system and appear in routine and special surface observations for the reporting location.
Plain English
An extra layer of weather reporting stations — usually run by trained people at smaller airports — that fill in gaps where the main automated weather stations don't reach. Their reports show up in the same aviation weather products pilots already use.
Context Anchor
You may see SAWRS in FAA acronym lists, airport weather reporting references, or discussions of local weather observations at airports.
Derivation
"Supplementary" comes from Latin supplementum, meaning something added to fill a gap. That's exactly what this system does — it adds reports from places the main weather network doesn't cover.
Why Pilots Care
If you're flying into a smaller airport, the weather report you're reading may be coming from a SAWRS observer rather than an automated station. Knowing the source helps you judge how current and complete the observation is.
Intuition Check
Do not read “supplementary” as “unofficial guesswork.” In this term, it means an added source of approved local weather observations that supports the main weather-reporting network.
Example Sentence 1
The weather report for that small mountain airport came from a SAWRS observer rather than an automated station.
Example Sentence 2
Before departing, the pilot confirmed the field had SAWRS coverage for current conditions.