Definition
Weather reports generated by unattended ground-based sensor systems located at or near an airport, which automatically measure surface conditions such as wind, visibility, ceiling, temperature, dew point, altimeter setting, and precipitation, and broadcast or transmit those readings on a continuous or scheduled basis. Common types include ASOS (Automated Surface Observing System), AWOS (Automated Weather Observing System), and AWSS (Automated Weather Sensor System).
Plain English
Machines at the airport that measure the weather on their own and broadcast the results, so pilots and controllers can hear current conditions without a human observer being present.
Context Anchor
Seen when checking airport weather before a departure or instrument approach, especially when deciding whether the reported ceiling and visibility meet the requirements for that operation.
Derivation
Automated comes from the Greek 'automatos,' meaning 'self-acting.' The word here signals that the observing is done by the equipment itself, not by a human weather observer. This matters because earlier weather reports relied on a person at the airport looking outside and writing down conditions.
Why Pilots Care
Pilots rely on these reports to determine if weather meets the minimums for an approach; however, some automated systems have limitations in reporting certain visibility or ceiling conditions accurately.
Intuition Check
Do not read automated as meaning perfect or complete. It means the report was generated by equipment; the actual weather can still change quickly or vary around the airport.
Example Sentence 1
Before starting the approach, the pilot tuned the AWOS frequency and listened to the automated weather observation to confirm the ceiling was above minimums.
Example Sentence 2
At remote airports, automated weather observations provide the only available METAR data for flight planning.