Definition
An unmanned, automated weather station that measures and reports surface weather conditions — typically wind, temperature, dew point, altimeter setting, and sometimes precipitation — at an airport or remote site, transmitting the data without a human observer present.
Plain English
A robotic weather station at an airport that takes measurements on its own and sends them out, with no person standing there reading the instruments.
Context Anchor
Seen in aviation weather information, airport references, and FAA acronym lists when identifying an automated source of local airport weather.
Derivation
‘Meteorological’ comes from the Greek meteoron, meaning ‘thing high in the air’ — the same root behind ‘meteor.’ So a meteorological observing system is, literally, a system that watches what is going on up in the air. ‘Automatic’ tells you no person is involved in the readings.
Why Pilots Care
Gives pilots current weather data needed for go/no-go decisions and safe flight planning when no human observer is available.
Intuition Check
Automatic does not mean the weather report is guaranteed perfect. It means sensors collect and report the observation without a person needing to take each measurement.
Example Sentence 1
The pilot pulled up the AMOS report for the small airfield to check the wind and altimeter setting before departure.
Example Sentence 2
Remote strips rely on AMOS to keep weather information available around the clock.