A typical METAR contains data for
the temperature, dew point, wind direction and speed, precipitation, cloud cover and heights, visibility, and barometric pressure
.
What does BKN mean in weather?
Cloud. Cloud amount is reported as FEW = few (1-2 oktas), SCT = scattered (3-4 oktas), BKN =
broken (5-7 oktas)
or OVC = overcast (8 oktas), followed by the height of the cloud base in hundreds of feet above aerodrome elevation e.g. SCT018 = scattered clouds at 1800 ft.
Why are METARs coded?
The METAR code
provides the direction of the wind relative to true north
, as well as the average wind speed expressed in knots. After the code that gives the direction and the average speed of the wind, another may appear in the form XXXVYYY, which indicates that the wind direction varies between XXX and YYY.
What kind of visibility is reported in the METARs report?
Surface (horizontal) visibility
is reported in METAR reports in terms of statute miles and increments thereof; e.g., 1/16, 1/8, 3/16, 1/4, 5/16, 3/8, 1/2, 5/8, 3/4, 7/8, 1, 1 1/8, etc.
How often are METARs generated?
The METAR only gives you a small snapshot in time. They are only good for an hour. They are usually
refreshed around 55 past the hour
. TAFs, on the other hand, cover a 24 to 30 hour period and they are published 6 times a day (0000, 0600, 1200, 1800).
What does V mean in METAR?
V –
Varying
. VIRGA – Virga. VRB – Variable. VRB VIS – Variable Visibility. VV – Vertical Visibility, indefinite ceiling.
What does 9999 mean in TAF?
The largest reportable metric value is. 9999. This value represents
a visibility greater than 9000
.
meters (7 SM or more)
. The contraction CAVOK (ceiling and visibility OK) may be used when there is no significant weather, the visibility is 10 km or greater, and the ceilings are greater than 5,000 ft.
What does METARs stand for?
METAR is the international standard code format for hourly surface weather observations which is analogous to the SA coding currently used in the US. The acronym roughly translates from French as
Aviation Routine Weather Report
.
How long is an Airmet valid for?
AIRMETs are routinely issued for
6 hour periods
beginning at 0245 UTC. AIRMETS are also amended as necessary due to changing weather conditions or issuance cancellation of a SIGMET.
What is the T at the end of a METAR?
The “0” after the “T” indicates that the
temperature and dew point are higher than 0 degrees Celsius
(a “1” will follow the “T” when the dew point temperature and /or the temperature is / are less than 0 degrees Celsius).
Is Tower visibility controlling?
The visibility observed from an airport tower. According to current U.S. weather observing practice, at civil stations the control-tower visibility
becomes the official visibility for the station whenever the surface visibility becomes less than three miles
.
What does Shra mean in a TAF?
The weather groups shall be constructed by considering columns 1 to 5 in the table above in sequence; i.e., intensity, followed by description, followed by weather phenomena, e.g., heavy rain shower(s) is coded as +SHRA. To denote
moderate intensity
, no entry or symbol is used.
What does P mean in a METAR?
P. indicates greater
than the highest reportable value
.
PCPN
.
precipitation
. PL.
How are METARs generated?
Origin. METARs typically come from airports or permanent weather observation stations. Reports are
generated once an hour or half-hour at most stations
, but if conditions change significantly at a staffed location, a report known as a special (SPECI) may be issued. … (Such as KPLU which reports 3 per hour.)
How do I read METAR visibility?
In the US, “statute miles” are used, so in this case the visibility is
10 statute miles
(or higher). More commonly this will be expressed in meters, up to 9998. A reading of 9999 would indicate visibility of over 10 kilometers. A reading of 0000 indicates less than 50 meters visibility.
WHO issues SIGMETs?
NWS
has four Meteorological Watch Offices which issue SIGMETs: the National Centers for Environmental Prediction Aviation Weather Cen- ter (AWC), Alaskan Aviation Weather Unit (AAWU), the Honolulu Forecast Office and the Guam Forecast Office.
