Revision 2 Nov/2002
KMD 550/850 FIS Addendum
5
BASIC SERVICE WEATHER PRODUCTS
The following is a discussion of weather products offered with the basic
no-fee service. Accessing and navigating these services will be dis-
cussed in detail later in this addendum.
METAR
A METAR (Aviation Routine Weather Report) describes the specific
weather conditions at a particular airport at a given time. The elements
of a METAR are in order as follows:
1.
Type of report
2.
ICAO station identifier
3.
Date and time of issue
4.
Modifier (AUTO if automated report or COR if corrected observation)
5.
Wind
6.
Visibility
7.
Runway visual range (as required)
8.
Weather phenomena
9.
Sky condition
10. Temperature/dew point group
11. Altimeter
12. Remarks (as required)
METARs available within 50 nautical miles of the selected area will be
displayed up to a maximum of 25 reports. These reports are displayed
in an encoded textual format. METARs displayed graphically on the
map are offered through a subscription service.
NOTE: When a specific element of METAR data is not available, it is
omitted from the report. The user must know the sequence of data to
recognize omissions. At the time of this printing, METAR observations
older than 75 minutes are discarded. Sometime in the first half of 2003
METAR observations older than 120 minutes will be discarded.
See Appendix A, Understanding METARs, for instructions on decoding
textual METARs.
SPECI
A SPECI (Aviation Selected Special Weather Report) is related to the
METAR. SPECIs are issued when certain specific conditions or events
have been observed at a particular location, usually an airport. A SPECI
will contain the same elements as a METAR and will generally be issued
for the following reasons:
Basic Service Weather Products
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