Chapter 1: Aviation Routine Weather Report's and Terminal Aerodrome Forecasts

CHAPTER ONE

AVIATION ROUTINE WEATHER REPORTS AND TERMINAL AERODROME

FORECASTS

100.

INTRODUCTION

This chapter introduces the student to the format and use of two meteorological products available

to aviators, the Aviation Routine Weather Report (METAR) and the Terminal Aerodrome Forecast

(TAF). The discussion will demonstrate the interpretation of each of these products, which use

numerous codes and abbreviations, as well as the differences among military METARs and TAFs

and those of the civilian and international community. Finally, this chapter will demonstrate how

to apply this knowledge to various flight planning situations.

The METAR and TAF are the most widely used methods of disseminating weather observations

and forecasts (respectively) to aircrew. They are also the quickest means, 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. 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, 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.

101.

LESSON TOPIC LEARNING OBJECTIVES

TERMINAL OBJECTIVE: Partially supported by this lesson topic:

1.0 Describe displayed data in Aviation Routine Weather Reports (METARs) and Terminal

Aerodrome Forecasts (TAFs).

ENABLING OBJECTIVES: Completely supported by this lesson topic:

1.1 State the use of METARs.

1.2 State the letter identifies used to report various types of METARs.

AVIATION ROUTINE WEATHER REPORTS AND TERMINAL AERODROME

FORECASTS 1-1