Terminal Aerodrome Forecasts (TAF) Use for Flight Planning

METEOROLOGY FLIGHT PLANNING

CHAPTER ONE

crossing. A letter "L" or "H" after the RH value will indicate to which altitude the RH

corresponds. A single slash after these altitudes indicates that more than three crossings occur,

and the number of additional crossings is noted after the slash. When a "00" appears for the RH,

this indicates an RH of 100%. If "20" is coded, this indicates that the RH is the lowest that can

be obtained. Two slashes, "//", indicate RH data is missing.

Examples:

RADAT 63017

Freezing level at 1700 feet MSL with 63% RH

RADAT 91L028039061

Freezing levels at 2800, 3900, and 6100 feet MSL

with 91%RH at 2800 feet

RADAT 84H008025085/1

Freezing levels at 800, 2500, and 8500 feet MSL

with 84% RH at 8500 feet, and one additional

crossing

RADAT ZERO

Freezing level at the surface

RADAT MISG

Unable to obtain, high winds, or equipment failure

RAICG 89MSL

Balloon iced up at 8900 feet MSL

107.

THE TERMINAL AERODROME FORECAST

Terminal Aerodrome Forecasts (TAF) Use for Flight Planning

Any aviator planning a flight should know both the destination's existing and forecasted weather.

Previously we learned the METAR provides existing weather. Now, we will discuss the surface

forecasted weather conditions by learning how to read TAFs. This teletype information will also

aid you in planning for the type of flight (IFR/VFR), type of approach you require, determining if

an alternate is required, and selection of the best alternate.

Although there are many differences in TAF reporting between the military and civilian weather

offices, as well as throughout the world, we will focus this discussion on the U.S. military TAF

since the bulk of your training flights will commence from military bases. Once this has been

accomplished, it will be much easier to point out differences existing among the TAFs of the

U.S. military, civilian, and international communities.

TAF Sequence

It will become readily apparent that each line of the TAF forecast will follow the same basic

sequence: message heading or change group, time, wind, visibility, weather and obstructions to

vision, clouds, altimeter, and remarks. The only deviation that occurs is the addition of wind

shear, temperature, icing, and turbulence groups when applicable. Figure 1-18 shows an example

of a single line forecast with a breakdown of each group. Figure 1-19 shows an actual forecast

for Navy Whiting Field.

AVIATION ROUTINE WEATHER REPORTS AND TERMINAL AERODROME

FORECASTS 1-17