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Pilot's Handbook of Aeronautical Knowledge
Aviation Weather Services

Aviation Weather Reports

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Pilot's Handbook of Aeronautical Knowledge

Preface

Acknowledgements

Table of Contents

Chapter 1, Introduction To Flying
Chapter 2, Aircraft Structure
Chapter 3, Principles of Flight
Chapter 4, Aerodynamics of Flight
Chapter 5, Flight Controls
Chapter 6, Aircraft Systems
Chapter 7, Flight Instruments
Chapter 8, Flight Manuals and Other Documents
Chapter 9, Weight and Balance
Chapter 10, Aircraft Performance
Chapter 11, Weather Theory
Chapter 12, Aviation Weather Services
Chapter 13, Airport Operation
Chapter 14, Airspace
Chapter 15, Navigation
Chapter 16, Aeromedical Factors
Chapter 17, Aeronautical Decision Making

Appendix

Glossary

Index

3. Synopsis—an overview of the larger weather picture.
Fronts and major weather systems that affect the
general area are provided.
4. Current conditions—this portion of the briefing contains
the current ceilings, visibility, winds, and temperatures.
If the departure time is more than 2 hours away, current
conditions are not included in the briefing.
5. En route forecast—a summary of the weather forecast
for the proposed route of flight
6. Destination forecast—a summary of the expected
weather for the destination airport at the estimated
time of arrival (ETA).
7. Winds and temperatures aloft—a report of the winds
at specific altitudes for the route of flight. The
temperature information is provided only on request.
8. Notices to Airmen (NOTAM)—information pertinent
to the route of flight which has not been published
in the NOTAM publication. Published NOTAM
information is provided during the briefing only when
requested.
9. ATC delays—an advisory of any known ATC delays
that may affect the flight
10. Other information—at the end of the standard briefing,
the FSS specialist provides the radio frequencies
needed to open a flight plan and to contact EFAS. Any
additional information requested is also provided at
this time.

Abbreviated Briefing
An abbreviated briefing is a shortened version of the standard
briefing. It should be requested when a departure has been
delayed or when weather information is needed to update the
previous briefing. When this is the case, the weather specialist
needs to know the time and source of the previous briefing
so the necessary weather information will not be omitted
inadvertently. It is always a good idea to update weather
whenever a pilot has additional time.

Outlook Briefing
An outlook briefing should be requested when a planned
departure is 6 hours or more away. It provides initial forecast
information that is limited in scope due to the time frame of
the planned flight. This type of briefing is a good source
of flight planning information that can influence decisions
regarding route of flight, altitude, and ultimately the go/no-go
decision. A prudent pilot requests a follow-up briefing prior
to departure since an outlook briefing generally only contains
information based on weather trends and existing weather in
geographical areas at or near the departure airport. A standard
briefing near the time of departure ensures that the pilot has
the latest information available prior to their flight.

Aviation Weather Reports

Aviation weather reports are designed to give accurate
depictions of current weather conditions. Each report
provides current information that is updated at different
times. Some typical reports are METAR, PIREPs, and radar
weather reports (SDs).

Aviation Routine Weather Report (METAR)
A METAR is an observation of current surface weather
reported in a standard international format. While the
METAR code has been adopted worldwide, each country is
allowed to make modifications to the code. Normally, these
differences are minor but necessary to accommodate local
procedures or particular units of measure. This discussion of
METAR will cover elements used in the United States.

Metars are issued hourly unless significant weather changes
have occurred. A special METAR (SPECI) can be issued at
any interval between routine METAR reports.
Example:
METAR KGGG 161753Z AUTO 14021G26 3/4SM
+TSRA BR BKN008 OVC012CB 18/17 A2970 RMK
PRESFR

A typical METAR report contains the following information
in sequential order:
1. Type of report—there are two types of METAR
reports. The first is the routine METAR report that
is transmitted every hour. The second is the aviation
selected SPECI. This is a special report that can be
given at any time to update the METAR for rapidly
changing weather conditions, aircraft mishaps, or
other critical information.
2. Station identifier—a four-letter code as established
by the International Civil Aviation Organization
(ICAO). In the 48 contiguous states, a unique three letter
identifier is preceded by the letter "K." For
example, Gregg County Airport in Longview, Texas, is
identified by the letters "KGGG," K being the country
designation and GGG being the airport identifier.

In other regions of the world, including Alaska and
Hawaii, the first two letters of the four-letter ICAO
identifier indicate the region, country, or state. Alaska
identifiers always begin with the letters "PA" and
Hawaii identifiers always begin with the letters "PH."
A list of station identifiers can be found at an FSS or
NWS office.

 

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