JPATS Weather - NETC

JPATS AVIATION WEATHER BOOKLET
JX106 - METARS AND TAFS
INTRODUCTION
The Aviation Routine Weather Report (METAR) and the Terminal Aerodrome Forecast (TAF)
are the most widely used methods of disseminating weather observations and forecasts
(respectively) to aircrew. They are also the quickest means, as well, because they contain only
letters and numbers. Years ago, when Teletype was the quickest means of information
dissemination, METARs and TAFs were distributed across the country and overseas by this
method, as well. Today, even though electronic communication is an important part of the
existing military and civilian weather networks, the same basic character set is used, and these
reports are still often called “teletype” products.
The METAR and TAF formats have not changed greatly over recent years, except to conform
better to international standards. Thus, these formats contain certain codes, which–while they
may be cumbersome at first–provide users with precise weather information because of their
clear and exact nature.
Once the interpretation of a METAR has been discussed, the TAF format should then be easier
to understand, since they use similar data groups. The TAF, however, is usually longer since it is
a forecast covering a greater period of time. As such, the TAF format has additional rules that
must be understood before an aviator can apply the forecast information to a particular situation.
Following the discussion of these topics, this chapter will point out the major differences
between the military TAF and its civilian and international counterparts. Finally, this chapter will
demonstrate how to apply this knowledge to various flight planning situations.
REFERENCES
AFH 11-203, Weather for Aircrews, Volume 2
DoD Flight Information Publication (FLIP) General Planning, Chapter 8
THE AVIATION ROUTINE WEATHER REPORT (METAR)
Aviation Routine Weather Reports (METAR) provide a rapid and efficient means of transmitting
the latest observed weather information for various stations throughout the world. These reports
are transmitted over available computer/teletype circuits.
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