The Winds and Temperatures Aloft Forecast (FD) gives an estimate of wind
direction as it relates to true north, the wind speed (in knots) and the
temperature (degrees Celsius) for selected levels of altitude.
Winds and Temperatures Aloft Forecast (FD) is shown below.
FD KSJC 161640
DATA BASED ON 161200Z
VALID 16180Z FOR USE 1700 -2100Z TEMPS NEG ABV 24000
FT 3000 6000 9000 12000 18000 24000
HOU 2619 2728+01 2635-05 2641-09 2654-21 2665-32
JOT 2526 2736+01 2642-06 2649-11 2662-22 2674-33
Line1 Winds and Temperature Aloft (FD), San Jose International Airport,
CA, 16th day of month, time: 1640.
Line2 States that the forecast is
based on observations made on the 16th day of the month at 1200 Zulu
Line3 Report is valid on the 16th day of the month at 1800 Zulu
time and is to be used from 1700 - 2100 Zulu time. Temperatures above 24,000
feet are always negative, this note indicates that the negative sign (-) is not
shown on numbers for 30,000 feet and above.
Line 4 This line contains
the column headings for the information now shown in chart form. Each column
indicates the altitude at which the winds and temperatures were measured. These
are recorded in feet (FT) beginning with 3,000 and as this is a partial chart
only going up to 24,000 feet.
Line5 Location identification code (HOU)
for Houston, Texas. The next group of 6 numbers is broken up by pairs. The first
2 digits (26) give the true direction from which the wind is blowing which is
260 degrees. The second pair of digits (19) gives the wind speed in knots (19
knots). The third pair of numbers indicate the temperature, however temperatures
are not reported for 3,000 feet and less. So, going to the second group of
numbers (2728-01) the information tells us that at 6,000 feet the winds are from
270 degrees with a windspeed of 28 knots and a temperature of 1 degree C.
Line 6 This line contains information for Joliet, IL (JOT) and is
read the same as above.