Terminal Forecasts (FT) is one of the best sources for predicting what the
weather at a particular airport (terminal) will be in the future. These forecast
predictions cover an area within 5 nautical miles of the center of the runway
field. FTs are usually issued 3 times a day and are valid for accuracy up to 24
hours. The first section of the FT covers the expected weather for the upcoming
18-hour period. This includes information about ceiling, visibility, vision
obstructions, wind and expected weather changes at that facility.
A
sample Terminal Forecast (FT) is
JAN 251010 C5 X 1 S-BS 3325G35 OCNL CO X OS+ BS.
16Z C30 BKN 3BS 3320 CHC SW-. 22Z 20 SCT 3315. 00Z CLR.
04Z VFR WND . .
REPORT CODE
INFORMATION GIVEN
JAN
station/airport identifier
251010
date and time of report: day of the month followed by valid
times
C5 X
description of sky, clouds and ceiling level
1
number of statute miles of visibility; if no number given then
visibility is greater than 6 statute miles
S-BS
weather and obstructions to vision (see code from Surface Aviation
report)
3325G35
wind description; absence of wind entry indicates that the wind is
less than 6 knots; winds are given in relation to true north
OCNL CO X OS+ BS
Specially coded remarks; OCNL = the conditions are expected to occur
less than half of the time during the time period given
Expected changes over the next 18 hours at this terminal; a number
followed by a "Z" indicates the time at which the change is expected to
occur
04Z VFR WND . .
Six-hour categorical outlook which gives the start time to which one
adds 6 hours and gets the ending time for this time period; if the
contraction "WND" is added to "VFR" it means that winds of 25 knots or
stronger are expected during this time period; a double period indicates
the end of the report . .
Terminal Forecast decoded
below:
Jackson, Mississippi is valid beginning on the 25th day of the
month at 1000Z until 1000Z on the 26th day of the month. The ceiling is expected
to be 500 feet, an obscured sky with 1 statute mile visibility; light snow and
blowing snow with wind from 330O at 25 knots gusting up to 35 knots; occasional
conditions of zero ceiling with obscured sky and zero visibility; accompanied
by heavy snow and blowing snow; by 1600Z ceiling will be 3,000 feet in altitude
and broken with visibility of 3 miles accompanied by blowing snow with wind from
330 degrees at 20 knots with a chance of light snow showers; by 2200Z scattered
clouds at 2,000 feet with a visibility of more than 6 miles, wind from 330
degrees at 15 knots; by 0000Z clear sky with visibility greater than 6 miles and
wind less than 6 knots; outlook from 0400Z to 1000Z has a ceiling of more than
3,000 feet, visibility greater than 5 miles (VFR) and wind 25 knots or stronger;
end of report.