Example
Phraseology
1/16SM
Visibility one sixteenth
14SM
Visibility one four
+RAGR
Heavy rain, hail
-FZRAPL
Light freezing rain, ice pellets
FEW010
Few clouds at one thousand
SCT015 BKN030
One thousand five hundred scattered, ceiling three thousand
broken
BKN010
Ceiling one thousand broken
SCT025 OVC300
Two thousand five hundred scattered, ceiling three zero
thousand overcast
02/M08
Temperature two, dew point minus eight
17/15
Temperature one seven, dew point one five
A2999
Altimeter two niner niner niner
A3017
Altimeter three zero one seven
Table 1-22 -- Example weather report code phraseology
Weather Observation Systems
Many airports throughout the National Airspace System are installing automated
weather observation systems. These systems use sensors to obtain and broadcast
valuable meteorological data to aircraft. This weather information can be extremely
important to aircraft operating in and out of uncontrolled airports. Two such systems are
the Automated Weather Observing System (AWOS) and the Automated Surface
Observing System (ASOS).
AWOS
AWOS is a real time system consisting of multiple sensors, a processor, a computer-
generated voice subsystem, and transmitter to broadcast local minute-by-minute
weather directly to aircraft that are operating up to 10,000 ft AGL and 25 nm from the
AWOS. AWOS has four operational levels:
AWOS A - Reports altimeter settings
AWOS I - Reports wind speed, wind gust, wind direction, variable wind direction,
temperature, dew point, altimeter, and density altitude
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