I occasionally see AO2
in the remarks of an automated weather report. What does the AO2 mean?
METAR KSLC 280453Z 00000KT 10SM FEW042 SCT055 BKN080 04/02 A2981 RMK AO2 CIG 037 NW RNWY SLP087 T00440022
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Sign up to join this communityThe AO2
notation means the station is automated and has a precipitation
discriminator. AO1
means automated but no precipitation discriminator. The precipitation discriminator will be able to sense the difference between rain and snow.
The METAR format is documented in the Federal Meterological Handbook No. 1 in Chapter 12. This particular notation is:
Type of Automated Station (AO1 or AO2). AO1 or AO2 shall be coded in all METAR/SPECI from automated stations. Automated stations without a precipitation discriminator shall be identified as AO1; automated station with a precipitation discriminator shall be identified as AO2.
AO1
in the remarks section of the METAR would still have a precipitation "sensor" but would not be able to discriminate between the types of precipitation (ex.: rain or snow).
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Feb 4, 2016 at 15:28