IRFP-01
Metro Review
(2) The usual 3-letter identifiers are preceded by a “K” for the
contiguous United States.
(3) Alaska and Hawaii will use 4-letter identifiers beginning
with “PA” and “PH” respectively.
(4) Changes are planned to incorporate 3-letter identifiers for
those weather reporting stations where numbers and
letters are now used (e.g., W10 to KHEF)
b. When
(1) 091730Z—the forecast for the 9th day of the month with an
issuance time of 1730Z or UTC (2-digit date and 4-digit
time)
(2) 091818—the valid period with the first 2 digits containing
the day of the month (09)
(3) 091818—the second 2 digits specify the hour beginning
the forecast period (1800Z)
(4) 091818—the last 2 digits are the hour ending the forecast
period (1800Z on the next day, the 10th)
c.
Wind
(1) WS015/30045KT means at 1,500 ft, we expect wind to be
300 degrees at 45 kts. This indicates low-level wind shear
not associated with convective activity
d. Time Periods, Etc.
(1) FM2030—From 2030Z or UTC time (indicates hours and
minutes)
(2) TEMPO 2022—Temporary changes expected between
2000Z and 2200Z
(3) FM2300—From 2300Z
(4) PROB40 0407—There is a 40% probability of this condition
occurring between 0400Z and 0700Z
(5) FM1000—From 1000Z
(6) BECMG 1315—Conditions becoming as described
between 1300Z and 1500Z
(8-97) Original
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