Name: High Wind in Montana, August 21, 2003
Start: 2003-08-21T03:06
End: 2003-08-21T03:06
Location: Montana

The toll

Deaths: 0
Injuries: 0
Property damage: None recorded
Crop damage: None recorded
Events: 1

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.

What happened

The episode as NWS TFX wrote it up.

A wind gust of 62 mph occurred at Chinook 11S.

What forecasters said that day

The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Great Falls, MT wrote its last area forecast discussion before the first event at Aug 21, 2:12 AM MST, 54 minutes earlier.

Area forecast discussion, Aug 21, 2:12 AM MST, 54 minutes before

SOUTHWEST AND NORTH CENTRAL MONTANA FORECAST
NATIONAL WEATHER SERVICE GREAT FALLS MT2
312 AM MDT THU AUG 21 2003

.DISCUSSION...

TODAY AND TONIGHT...UPPER LEVEL RIDGE AXIS OVER CENTRAL MONTANA THIS
MORNING WILL MOVE INTO EASTERN MONTANA DURING THE AFTERNOON...
ALLOWING FOR WEAK SOUTHWEST FLOW ALOFT TO DEVELOP OVER OUR CWA.
WARMER TEMPS MOVING IN ALOFT SHOULD TRANSLATE INTO A 5-10 DEGREE RISE
FROM HIGH TEMPS YESTERDAY ACROSS NORTH AND CENTRAL ZONES. AN UPPER
LEVEL DISTURBANCE WILL MOVE INTO SOUTHWEST MONTANA LATE THIS
AFTERNOON AND EVENING...BRINGING ISOLATED SHOWERS AND THUNDERSTORMS.
WITH THE LOWER TROPOSPHERE ANTICIPATED TO REMAIN VERY DRY...GUSTY
WINDS ARE POSSIBLE WITH A FEW STORMS. HOWEVER...LIMITED MOISTURE WILL
INHIBIT CONVECTION OVERALL. SINCE COVERAGE IS EXPECTED TO BE
ISOLATED...NO FIRE WEATHER WATCHES OR WARNINGS WILL BE ISSUED.
ISOLATED CONVECTION SHOULD DIMINISH AFTER MIDNIGHT.

FRIDAY AND FRIDAY NIGHT...SUBTROPICAL MOISTURE WILL INCREASE ACROSS
THE AREA FRIDAY AFTERNOON AS SOUTHWEST FLOW ALOFT STRENGTHENS. A FEW
DISTURBANCES WILL TRIGGER SHOWERS/T-STORMS OVER THE SOUTHWEST DURING
THE AFTERNOON...WITH ACTIVITY MOVING INTO CENTRAL AREAS DURING THE
EVENING. PRECIPITABLE WATER VALUES ARE FORECAST TO RISE TO AROUND ONE
INCH...SO T-STORMS SHOULD BE WET. ALSO...A COLD FRONT WILL SWEEP
THROUGH THE AREA FRIDAY NIGHT INTO SATURDAY MORNING. WINDS MAY BE
QUITE GUSTY BEHIND THE FRONT.

SATURDAY...BREEZY AND COOLER CONDITIONS WILL OCCUR BEHIND THE COLD
FRONT WITH DOWNSLOPE WINDS AND STRONG COLD AIR ADVECTION INHIBITING
PRECIP EAST OF THE DIVIDE. THERE WILL BE JUST A SLIGHT CHANCE OF
PRECIP OVER WEST AND SOUTHWEST ZONES WITH SOMEWHAT MOIST WESTERLY
FLOW ALOFT. VILLANI

SUNDAY THROUGH THURSDAY...CONFIDENCE IN FORECAST FOR THIS PERIOD IS
LOWER THAN NORMAL DUE TO MODEL DIFFERENCES AND ALSO MODEL RUN-TO-RUN
CONSISTENCIES HAVE BEEN NOTHING TO WRITE HOME ABOUT. EVEN IN EARLY
PART OF PERIOD MODELS HAVE SIGNIFICANT DIFFERENCES WITH RESPECT TO
AN UPPER TROUGH FORECAST TO MOVE THROUGH THE AREA. LATEST GFS HAS A
FAIRLY SHARP UPPER TROUGH MOVING THROUGH SUN NIGHT. ECMWF IS WEAKER
AND A LITTLE FASTER WHILE UKMET IS MUCH MUCH SLOWER MOVING THE UPPER
TROUGH THROUGH MON NIGHT. INHERITED FORECAST WHICH HAD SOME MENTION
OF PRECIPITATION OVER THE NRN ZONES FOR SUN NIGHT LOOKS OK SO WILL
CONTINUE WITH IT. WOULD EXPECT SOME COOLING BEHIND THE UPPER TROUGH
ON MON SO LOWERED HIGHS SEVERAL DEGREES IN THE N. BLANK

.CCF NUMBERS
GTF UB 088/056 091/059 084 16002
    BBBUU 052/080 045/077 045/080 050/083 053 50002000000
CTB UB 084/052 087/055 078 16002
    BBBUU 050/076 042/072 042/075 050/078 053 40003000000
HLN UB 091/057 093/061 085 160-4
    BBUUU 054/083 050/082 050/084 055/085 058 52100000000
BZN UB 090/052 091/054 084 16113
    BBUUU 049/084 046/083 046/084 050/085 054 41200000000
WEY UB 086/045 086/047 080 16233
    BBUUU 040/080 037/078 037/078 041/078 042 32200000000
DLN UB 088/056 088/056 084 16114
    BBUUU 052/083 049/083 049/084 051/085 052 42200000000
HVR UU 090/055 094/060 088 16002
    BBBUU 053/083 047/079 047/082 053/083 058 30003000000
LWT UB 086/054 089/058 085 16002
    BBBUU 053/080 044/077 044/080 048/080 055 3-103000000

.TFX...NONE.

Hazardous weather outlook, Aug 20, 5:00 AM MST, 22 hours 6 minutes before

MTZ008>015-044>055-210010-
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREAT FALLS MT
600 AM MDT WED AUG 20 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH CENTRAL AND SOUTHWEST
MONTANA

.DAY ONE...TODAY

A RED FLAG WARNING REMAINS IN EFFECT THROUGH THIS AFTERNOON FOR
CENTRAL AND NORTHERN MONTANA. SEE WWUS85 KTFX/GTFRFWTFX FOR FURTHER
DETAILS.

A RED FLAG WARNING REMAINS IN EFFECT THROUGH THIS AFTERNOON FOR
EASTERN AND SOUTHERN GALLATIN COUNTY AND THE EXTREME EAST PORTION OF
MADISON COUNTY. SEE WWUS85 KTFX/GTFRFWBYZ FOR FURTHER DETAILS.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

THERE IS A THREAT OF THUNDERSTORMS WITH LITTLE OR NO RAIN FRI AND
SAT

THERE IS A THREAT OF GUSTY WINDS FRI NIGHT INTO SUN MAINLY OVER THE
ROCKY MOUNTAIN FRONT BUT ALSO POSSIBLY FARTHER EAST AND SOUTH AS
WELL.

.SPOTTER INFORMATION STATEMENT...

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.

Event by event

1 high wind. Local standard time, as filed.

High Wind, Blaine

When: August 21, 3:06 AM MST
Where: Blaine forecast zone
Measured: 54 kt (62 mph) measured gust
Reported by: AWOS,ASOS,MESONET,ETC

What these are

High Wind: Sustained non-thunderstorm winds of 40 mph or more for an hour, or gusts of 58 mph or more.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

More

Every storm in Montana in 2003 Every state in 2003 This day in weather history Warnings in Montana, August 2003

Sources

NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 5377573.