Winds aloft

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[edit] Winds Aloft

Winds Aloft or official known as Winds and Temperature Aloft Forecast (FD) is forecast for specific atmospheric conditions in terms of wind and temperature in a specific altitude messured mostly in feet (ft) above mean sea level (MSL). The forecast is specificly used for aviation purpose.

The componets of a Winds and Temperature Aloft Forecast are displayed like: DD ss +/- TT

  • Wind and Wind Direction (displayed in a 4-digit number like 3127, which means a wind direction of DD=31 => 310 degree True North with a wind speed of ss=27 => 27 knots (knots = nautical miles per hour))
  • Temperature (displayed in a +/- 2-digit number like TT=-12, which means -12 degree Celsius)


[edit] Example

FBUS31 KWNO 190440

DATA BASED ON 190000Z DATA VALID 190600Z FOR USE 0600-1200Z.

TEMPS NEG ABV 24000

(means that temperatures above 24000ft are negative in general and a minus is not shown.)


FT 3000 6000 9000 12000 18000 24000 30000 34000 39000 (feet)

ABR 1027 1326+01 1428-03 1431-09 1639-21 1749-34 175849 175957 174758

ABI 2849+04 2857-02 2760-07 2670-20 2682-32 760344 760648 259451

ALS (etc.)

(ABR, ABI or ALS are the station abbreviations used in this report)


This forecast is made twice a day based on 00Z and 12Z data. (the Z stands for Zulu and means GMT time). The forecasts are valid 6 h(FD1/8), 12 h(FD2/9), and 24 (FD3/10) hours after the observation date/times of 0000Z and 1200Z upon which they are based. Dependent upon station elevation, FD1/2/3 wind forecasts are issued for the following levels: 3, 6, 9, 12, 18, 24, 30, 34, and 39 thousand foot levels.

The first level for which a wind forecast is issued is 1,500 feet or more above the station elevation. Temperature is forecast for all wind levels, except the 3,000 foot level, that are 2,500 feet or more above the station. The minus signs are deleted preceding the temperatures at the 30, 34, and 39  thousand foot levels. FD8/9/10 are for the 45,000 and 53,000  foot levels.

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