Different types
of weather reports and weather forecasts in the aviation
world.
METAR stands for
Aviation Routine Weather Report.
METAR is an observation
of the actual weather, this means that the weather that are reported in the
MEATR, is the actual weather for that airport.
The
METAR is taken every hour, or the non-routine special aviation weather report
called SPECI. The SPECI weather observation is an unscheduled report that’s
indicating a significant change from the previous METAR, in one or more
elements.
Here
is an example of how a METAR can look.
METAR KHWO 121856Z AUTO 27005KT 2 SM +RABR OVC007 17/16
A2980
METAR What type of
report
KHWO Station identifier, each station
that is reporting is listed by a four letter ICAO
identifier.
KHWO
is Hollywood North Perry Airport
121856Z time of METAR report, the date 12 is
day of month 1856 is the time in ZULU time
UTC,
The
report in this example was issued on the 12th of the month at 1856Z
time.
AUTO When a METAR is created totally by a
automated weather observation station, the modifier AUTO follows the date time
.
In
the remarks section the type of sensor will be reported A01 is a station without
a precipitation discriminator, this means that the station cannot difference the
precipitation, for example between water or
snow.
A02
have the capabilities to discriminate the difference between
precipitations.
27005KT Wind information, the wind direction
are reported in a five digit group, or if the wind is speed is higher than 99
knots, it is six digits.
The
first three digits represents the direction from which the wind is blowing, the
wind direction is with reference to the true
north.
If
the wind direction is variable the letters VRB is
used.
The
next digits show the speed of the wind. The wind speed is reported in
Knots.
In
the example above, the wind direction is from 270 which is west, and the speed
is 05 knots.
If
the wind was gusty it will be reported with a G, and followed by the highest
gusty winds.
For
example 27020G35KT
2 SM Visibility, visibility is reported
in statue miles SM, in this example we have a visibility of two statue miles.
The type of visibility here is Prevailing Visibility, that means that it is the
greatest distance an observer can see and identify objects through at least half
of the horizon.
Sometimes you can see RVR runway visual range be reported following
prevailing visibility,
RVR
is based on what a pilot in a moving aircraft should see when looking down the
runway. RVR is
Designated with an R followed by the runway number for example
R09L/2300FT.
This
means runway 09 Left visual range 2300 feet.
+RABR Weather Phenomena, this covers seven
types of precipitation, eight kinds of obscurations, and also five other weather
events. The code in the example here +RABR, is heavy rain and
mist.
This
is a weather condition that will reduce the visibility significant.
Here
is a list of the different codes for weather
phenomena.
Precipitation
RA-Rain
DZ-Drizzle
IC- Ice
crystals
GR-Hail
GS-Small hail/snow
pellets
SG-Snow
grains
PE-Ice
Pellets
Obstructions to
visibility
FG-Fog
BR-Mist
FU-Smoke
HZ-Haze
PY-Spray
SA-Sand
DU-Dust
VA-Volcanic
ash.
Other weather Phenomena
SQ-Squall
DS-Dust
storm
FC-Funnel Cloud, Tornado,
waterspout
SS-Sandstorm
PO-Dust/sand
whirls
OVC Sky condition, the amount of clouds
covering the sky is reported in eights or octas of sky
cover.
CLR
is clear.
FEW
is when the cloud coverage is 1/8 to 2/8 of the
sky.
SCT,
scattered clouds, cover 3/8 to 4/8 of the
sky.
BKN
broken clouds covering 5/8 to 7/8 of the
sky.
OVC,
is overcast.
007 Height of the sky condition, in this
example the overcast is 700 feet AGL Above Ground
Level.
17/16 Temperature and Dewpoint, the air
temperature and dewpoint is reported in degrees
Celsius.
In
this example the temperature is 17 Celsius and the dewpoint 16
Celsius.
If
the temperature is below 0 degrees Celsius it is reported with a M
before.
If
it is minus 2 celsius, it is reported M02.
A2980 The altimeter setting is reported in
inches of mercury.
RMK Remakrs, sometimes in a METAR, there can be
remarks.
The
types of information included in remarks, are wind data, variable visibility,
beginning and ending times of different weather
phenomena.