observed and must be within 5 minutes before the
scheduled observation hour.
Special observations (SPECI)—observations
taken to note any significant change in the weather as
defined by NAVMETOCCOMINST 3141.2 and
NAVMETOCCOMINST 3144.1. The observation
time is the time that the significant weather element is
observed. SPECI observations are also used in the
event of an aircraft mishap, volcanic eruptions, and any
other phenomena designated by local authority.
While METAR observations contain complete
observation data, SPECI observations usually contain
data pertinent only to the significant event or local
requirement. Table II-1-1 of NAVMETOCCOMINST
3141.2 and table 2-1 of NAVMETOCCOMINST
3144.1 list which elements are reported for each type of
observation.
BASIC CODE FORM
The METAR code contains both a basic report
section and a supplemental or additive data section, as
shown in table 3-1. In addition, remarks may be coded
or in plain language.
By regional decision, coded
additive data groups may be added to the reports. Any
missing elements are simply left out of the report. Keep
in mind there are minor code differences between
reporting stations in the United States and activities
located outside of the continental United States
(OCONUS).
BASIC METAR CODED
REPORT
The basic coded METAR report contains
identification data, wind, visibility, weather, sky
coverage, temperature, dew-point temperature, and
altimeter setting.
Identification Data
Identification data in a METAR or a SPECI
observation consists of the observation type (METAR
or SPECI), the station identifier, and the observation
time.
ICAO STATION IDENTIFIER.—CCCC. The
first letter indicates the country, while the remaining
three letters identify the actual station. These identifiers
are designated by the International Civil Aviation
Organization (ICAO) and are used to identify each
aviation terminal, including military stations. A list of
approved identifiers can be found in FAA Order 7350.6,
Location Identifiers.
UTC TIME.—YYGGggZ. METAR observations
are identified with the date and actual time of the
observation in UTC time. SPECI observations are
identified with the time that the SPECI observation
criteria was met. YY is the day, GG is the hours, and gg
is the minutes (00 in a METAR observation, the actual
time in minutes for a SPECI observation). Z is the
indicator for UTC time. The date is not recorded on
either observation form but is for dissemination
purposes only.
Report Modifiers
A report modifier may or may not appear in the
report. The report modifier AUTO is used by
automated stations. The report modifier COR indicates
the report was retransmitted with corrected data. Use
the same time as the original report.
Table 3-1.—METAR and SPECI Code Format
SYMBOLIC FORMAT OF METAR/SPECI CODES:
Basic Reporting Code
METAR or SPECI CCCC YYGGggZ AUTO/COR dddff(f)Gfmfm(fm)KT
dndndnVdxdxdx VVVVVSM RDRDR/VRVRVRVRFT or
RDRDR/VNVNVNVNVVXVXVXVXFT w'w' NSNSNShShShS or VVhShShS or
SKC T'T'/T'dT'd APHPHPHPH RMK SLPppp
Supplemental Reporting Code
Note: When a specific phenomenon does not occur, the group or group suffix is not reported.
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