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KMD 250 Pilot's Guide
Section 2
FIS Operation
Rev 4 Aug/2007
5. This line indicates that CONVECTIVE SIGMET 20C is VALID
UNTIL 2055Z time. Expiration time is two hours after issuance, but
Convective SIGMETs are issued hourly and replace the previous
hour’s product.
Each subsequent report issued for this same weather phenomenon
would increment the number. For example, 21C, 22C and so on.
6. Area of coverage by state ND (North Dakota) and SD (South
Dakota) or geographic area. In addition to state abbreviations, other
area abbreviations may be seen here, such as FL CSTL WTRS
(Florida Coastal Waters).
7. Location of weather phenomenon (may be an area, single cell or
line). Three letter designators for navaids or airports are used to
describe boundaries of coverage.
The starting and ending point are identical for an area
of thunder-
storms, like this: FROM 90W MOT-GFK-ABR-90W MOT (from 90
nm west of Minot, ND to Grand Forks, ND to Aberdeen, SD to 90
nm west of Minot, ND).
A Single Cell
thunderstorm 35 nm west of Kansas City would look
like this: 35WMKC
A Line of severe thunderstorms would look like this: FROM 90SE
SGF-70NE TXK-50NE LFK (from 90 nm southeast of Springfield,
MO to 70 nm northeast of Texarkana, AR to 50 nm northeast of
Lufkin, TX).
8. Details of weather phenomenon. Convective SIGMET details are
mostly in plain language with some abbreviations. This example is
typical for an area of severe thunderstorms:
INTSFYG (intensifying) AREA (of) SVR TSTMS (severe thunder-
storms) MOVG (moving) FROM 2445 (240 degrees at 45 knots).
Storm TOPS ABV (above) FL450 (flight level 4-5-0). WIND GUSTS
TO 60KT (knots) RPRTD (reported). TORNADOES…HAIL TO 2 IN
(inches in diameter)…WIND GUSTS TO 65 KT (knots) PSBL (pos-
sible) in the ND PTN (North Dakota portion).
For a single cell thunderstorm:
ISOLD (isolated) SVR TSTM (severe thunderstorm) D30 (30 nm in
diameter) MOVG (moving) FROM 2520 (250 degrees at 20 knots).
Storm TOPS ABV (above) FL450 (flight level 4-5-0). HAIL TO 2 IN
(inches in diameter) WIND GUSTS TO 65 KT (knots) PSBL (pos-
sible).
For a line of thunderstorms 25 nm wide:
LINE (line of) SVR TSTMS (severe thunderstorms) 25 MI WIDE
MOVG (moving) FROM 2745 (270 degrees at 45 knots). Storm
Understanding Weather Reports
KMD 250 FIS_R4 8/13/07 10:07 AM Page 2-77