4/20/23
AIM
EXAMPLE
−
VIS N2
−
visibility north two
7. Runway Visual Range (When Reported).
“R” identifies the group followed by the runway heading
(and parallel runway designator, if needed) “/” and the visual range in feet (meters in other countries) followed
with “FT” (feet is not spoken).
(a) Variability Values.
When RVR varies (by more than on reportable value), the lowest and highest
values are shown with “V” between them.
(b) Maximum/Minimum Range.
“P” indicates an observed RVR is above the maximum value for this
system (spoken as “more than”). “M” indicates an observed RVR is below the minimum value which can be
determined by the system (spoken as “less than”).
EXAMPLE
−
R32L/1200FT
−
runway three two left R
−
V
−
R one thousand two hundred.
R27R/M1000V4000FT
−
runway two seven right R
−
V
−
R variable from less than one thousand to four thousand.
8. Weather Phenomena.
The weather as reported in the METAR code represents a significant change in
the way weather is currently reported. In METAR, weather is reported in the format:
Intensity/Proximity/Descriptor/Precipitation/Obstruction to visibility/Other
NOTE
−
The “/” above and in the following descriptions (except as the separator between the temperature and dew point) are for
separation purposes in this publication and do not appear in the actual METARs.
(a) Intensity
applies only to the first type of precipitation reported. A “
−
” denotes light, no symbol
denotes moderate, and a “+” denotes heavy.
(b) Proximity
applies to and reported only for weather occurring in the vicinity of the airport (between
5 and 10 miles of the point(s) of observation). It is denoted by the letters “VC.” (Intensity and “VC” will not
appear together in the weather group).
(c) Descriptor.
These eight descriptors apply to the precipitation or obstructions to visibility:
TS
. . . . . . . . . . . thunderstorm
DR
. . . . . . . . . . . low drifting
SH
. . . . . . . . . . . showers
MI
. . . . . . . . . . . shallow
FZ
. . . . . . . . . . . freezing
BC
. . . . . . . . . . . patches
BL
. . . . . . . . . . . blowing
PR
. . . . . . . . . . . partial
NOTE
−
Although “TS” and “SH” are used with precipitation and may be preceded with an intensity symbol, the intensity still applies
to the precipitation,
not
the descriptor.
(d) Precipitation.
There are nine types of precipitation in the METAR code:
RA
. . . . . . . . . . rain
DZ
. . . . . . . . . . drizzle
SN
. . . . . . . . . . snow
GR
. . . . . . . . . . hail (
1
/
4
” or greater)
GS
. . . . . . . . . . small hail/snow pellets
PL
. . . . . . . . . . ice pellets
SG
. . . . . . . . . . snow grains
IC
. . . . . . . . . . . ice crystals (diamond dust)
UP
. . . . . . . . . . unknown precipitation (automated stations only)
Meteorology
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1
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