APPENDIX D
WEATHER FORECASTS
STUDENT HANDOUT
TERMINAL LEARNING OBJECTIVE: Acting as an aviator and given an IFR or VFR flight
mission and available weather information, the student will plan the flight for
weather considerations in accordance with (IAW) AR 95-1 and
FM 1-230.
SAFETY CONSIDERATIONS: None.
TRAINING RISK ASSESSMENT CODE: L.
ENVIRONMENTAL CONSIDERATIONS: None.
ENABLING LEARNING OBJECTIVE: Given pertinent information about a terminal
aerodrome forecast, the student will identify and interpret the information
contained in the forecast IAW FM 1-230.
1.
Terminal Aerodrome Forecast (TAF).
a. Definition. A Terminal Aerodrome Forecast (TAF) is a concise statement
of the expected meteorological conditions at an airport during a specified period
(usually 24 hours).
(1)
Issued by the National Weather Service for a defined area.
(2)
Prepared one-half hour prior to scheduled transmission times.
(3)
Scheduled for transmission four times daily 0000Z, 0600Z, 1200Z, and
1800Z.
b.
c.
TAF report elements.
(1)
Type of report.
(2)
ICAO station identifier.
(3)
Date and time of origin.
(4)
Valid forecast date and time.
(5)
Forecast meteorological conditions.
Probability forecast.
(1) PROB30 or PROB40 is used when the occurrence of thunderstorms or
precipitation is in the 30 percent to less than 50 percent range.
(2) PROB30 or PROB40 will not be shown during the first six hours of a
forecast.
d. Forecast change indicators are used when either a rapid, gradual, or
temporary change is expected in some or all of the forecast conditions.
(1) From group—-FM is used when a rapid change, usually occurring in
less than one hour, in prevailing conditions is expected.

FM 0115 SKC—-“After zero-one-one-five zulu, sky clear.”
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(2) Becoming group—-BECMG is used when a gradual change is expected over
a longer period of time, usually two hours.
overcast.
1600Z.”
 OVC012 BCMG 1416 BKN020--“Ceiling one-thousand-two-hundred
Then a gradual change to ceiling two-thousand broken between 1400Z and
(3) Temporary group-—TEMPO is used for any conditions in wind,
visibility, weather, or sky conditions which are expected to last for less than
one hour at a time, and are expected to occur during less than half the time
period.
 4SM HZ TEMPO 0006 2SM BR HZ--“Visibility four in haze with
occasional visibility two in mist and haze between 0000Z and 0600Z.”
NOTE:
Qualifiers and weather phenomena are the same as the METAR report.
(1) P6SM – visibility greater than 6SM
(2) NSW – No significant weather expected
(3) CB only cloud type shown in TAF
(4) Wind Shear – WS010/18040
(5) QNH 3020 INS – Forecasted altimeter setting
NOTE:
9999 – also means visibility greater than 6 sm on military TAF.
TAF
TAF
KMGM 091750Z
FM 2030
FM 0300
FM 1200
KPNS 091755Z
FM 2200
FM 0300
FM 1200
091818Z 22020KT 5SM HZFU SCT010 BKN250
30015G25KT 2SM BKN030 PROB40 2224 30010KT 2SM SHRA OVC010
28010KT 2SM TSRA BKN250
27005KT 4SM FG OVC008
091818 16008KT 5SM FGHZ SCT030 BKN040
16010KT 4SM FG SCT020 BKN030
19010KT 7SM BKN040 TEMPO 0709 00000KT 5SM BKN008
19010KT 6SM OVC040
KTCL 091753Z 091818 22020KT 3SM –SHRA BKN020
FM 2030 24010KT WSO15/30045KT 3SM SHRA OVC015
FM 2300 22010KT 5SM –SHRA BKN020 OVC040
FM 1000 22010KT 5SM –SHRA OVC020
BECMG 1315 20010KT P6SM SKC
KBHM 091750Z
FM 2100
FM 2400
FM 1000
091818 13020KT 6SM BKN030
15015KT 5SM FG SCT020 BKN030
14010KT 7SM BKN040 CB
15005KT 7SM CLR
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KANB 091755Z 091818 26015KT 4SM –SHRA SCT030 BKN050
FM 2300 24015G25KT 2SM +SHRA OVC040
BECMG 2401 24010KT 5SM –SHRA OVC050
FM 1000 27005KT 7SM SCT030 BKN050 OVC080
KATL 091752Z
FM 2030
FM 0200
FM 1000
091818 03005KT 10SM SCT030 SCT060
03015KT 6SM –SHRA BKN030
00000KT 2SM FG OVC020
04010KT 3SM HZ SCT030 OVC050
KDHN 091754Z 091818 00000KT 1/2SM FG V V003
BECMG 2022 02005KT 2SM FGHZ
FM 0100 03010KT 3SM –SHRA SCT008 BKN020
FM 1000 06015KT 4SM RA OVC020 TEMPO 1214 06010KT 1SM +SHRA OVC010
FM 1500 09010KT 5SM BKN010 BKN030 OVC060
ENABLING LEARNING OBJECTIVE: Given pertinent information about the winds aloft
forecast chart, the student will identify and interpret levels, direction of
winds, speed, and temperature IAW FM 1-230.
2.
Winds Aloft Forecast Chart.
a. Computer prepared and issued by the National Meteorological Center (NMC)
at Suitland, Maryland.
b.
Data issued to both civil and military weather stations.
c.
Valid for 12 hours.
d.
Forecast levels.
(1) Dependent on stations’ elevation, but usually for 6, 9, 12, 18, 24,
30, 34, and 39. Thousand-foot levels.
(2) Through 12,000 feet the levels are MSL altitude; 18,000 feet and
above are pressure altitude.
e.
Direction of wind.
(1) Referenced to true north,
to the nearest 10.
(2) The number by the wind arrow
is the middle digit of the wind direction.
f.
Speed.
(1) Indicated by using arrows
with flags (the same as on surface weather
charts).
(2) Less than 5 knots (99 – light
and variable).
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g.
Temperature.
(1) In degrees Celsius, given by a
number next to the station circle.
(2) Below zero temperatures
preceded by minus.
Wind 240 at 25 knots
Temperature 3 (C)
Wind 040 at 15 knots
Temperature 3 below zero (C)
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