Meteorology and Flight Planning
NOTE: The AWOS visibility is reported as
a runway visibility range and may differ
from the prevailing visibility.
(4) The reported sky condition/ceiling is
derived from the ceilometer located next to
the visibility sensor and may differ from the
observed sky condition, because the
AWOS is totally dependent on clouds over
the sensor site
There are four operational levels of AWOS
(1) AWOS-A - reports only altimeter setting
(2) AWOS-1 - reports altimeter setting, wind
data, temperature, dew point, and density
(3) AWOS-2 - reports information in AWOS-1
(4) AWOS-3 - reports information in AWOS-2
plus cloud and ceiling data
(5) AWOS information is transmitted over a
NOTE: The system transmits a 20- to
30-second weather message each minute.
The messages are updated each minute
and are receivable within 25 nm of the
AWOS site, at or above 3,000 ft AGL.
AWOS broadcasts phraseology generally
follows that used in other weather broadcasts.
The following are explanations of exceptions:
(1) The word "TEST" is added when the
system is not in commissioned status
(2) The phrase "TEMPORARILY
INOPERATIVE" is added when the system