A strong westerly flow aloft resulted in high winds along portions of the Northern Rocky Mountain Front. Wind gusts in excess of 60 mph were reported.
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.
The episode as NWS TFX wrote it up.
A strong westerly flow aloft resulted in high winds along portions of the Northern Rocky Mountain Front. Wind gusts in excess of 60 mph were reported.
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 Sep 23, 8:38 AM MST, 22 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREAT FALLS MT 938 AM MDT FRI SEP 23 2011 .UPDATE... TODAY...UPDATES TO ZONES NOT PLANNED...AN UPPER LEVEL HIGH PRESSURE RIDGE WILL CONTINUE TO KEEP THE AIRMASS WARM AND DRY. BREEZY CONDITIONS HAVE LEAD TO FIRE WEATHER AND HIGH WIND CONCERNS...AND WILL CONTINUE THE CURRENT RED FLAG WARNING AND HIGH WIND WARNING. CURRENT FORECAST LOOKS GOOD. ZELZER && .AVIATION... UPDATED 1135Z. HIGH PRESSURE ALOFT WILL CONTINUE TO PROVIDE DRY AND STABLE CONDITIONS. HIGH CLOUDS WILL MOVE ACROSS THE AREA AS AN UPPER LEVEL DISTURBANCE MOVES ACROSS SOUTHERN CANADA. SURFACE WINDS WILL BE BREEZY ACROSS THE PLAINS WITH THE STRONGEST WINDS ALONG THE NORTHERN ROCKY MOUNTAIN FRONT. SURFACE WINDS WILL DIMINISH AFTER 00Z. VFR CONDITIONS PREVAIL. && .FIRE WEATHER... UPDATED 1050Z. THE RED FLAG WARNING FOR ZONES 112...113...AND 114 WILL REMAIN IN EFFECT THROUGH THIS EVENING. WESTERLY WINDS ARE EXPECTED TO INCREASE UP TO BETWEEN 15 AND 25 MPH WITH GUSTS UP TO 40 MPH AT TIMES ACROSS WESTERN AND NORTHERN PORTIONS OF NORTH CENTRAL MONTANA. ALSO...AFTER GENERALLY POOR RECOVERY OVERNIGHT...RELATIVE HUMIDITIES WILL LIKELY FALL TO BETWEEN 10 AND 15 PERCENT ACROSS MOST OF THIS AREA. RELATIVE HUMIDITIES WILL ALSO LIKELY FALL TO BETWEEN 10 AND 20 PERCENT AT MOST OTHER LOWER ELEVATIONS...BUT WINDS WILL NOT BE QUITE AS BREEZY MOST PLACES. HOWEVER...PORTIONS OF CENTRAL MONTANA (FIRE ZONES 115 AND 117) WILL NEED TO BE MONITORED CLOSELY...AS THEY MAY APPROACH CRITICAL FIRE WEATHER CRITERIA. COULSTON && .PREV DISCUSSION... /ISSUED 535 AM MDT FRI SEP 23 2011/ TODAY THROUGH SUNDAY...A SHORTWAVE TROUGH MOVING OVER THE UPPER LEVEL RIDGE OF HIGH PRESSURE WILL CONTINUE TO BRING BREEZY WESTERLY WINDS AND HIGH CLOUDS TO THE NORTHERN AND CENTRAL PORTIONS OF THE TFX CWA TODAY. THE SURFACE PRESSURE GRADIENT IS STRONGEST ALONG THE ROCKY MOUNTAIN FRONT AND ALONG THE CANADIAN BORDER...AND THIS IS WHERE THE BREEZIEST WINDS WILL OCCUR (SEE FIRE WEATHER SECTION FOR DETAILS OF RED FLAG WARNING). EXCEPTIONALLY STRONG WINDS HAVE DEVELOPED ABOVE 5000 FEET ALONG THE NORTHERN ROCKY MOUNTAIN FRONT...INCLUDING LOGAN PASS...MARIAS PASS...AND THE DEEP CREEK AREA. OVERNIGHT...WINDS HAVE GUSTED TO AROUND 75 MPH AT LOGAN PASS AND TO AROUND 50 MPH NEAR DEEP CREEK. HAVE THEREFORE ISSUED A HIGH WIND WARNING FOR THESE AREAS THROUGH THIS EVENING. THESE WINDS...AND WINDS IN GENERAL...ARE EXPECTED TO GRADUALLY DECREASE THROUGH THIS EVENING AND INTO SATURDAY AS THE UPPER LEVEL RIDGE OF HIGH PRESSURE REBUILDS INTO THE AREA...WHILE SKIES REMAIN MOSTLY CLEAR. THE NEXT WEAK PACIFIC SYSTEM TO AFFECT THE AREA WILL APPROACH FROM THE WEST ON SUNDAY. FORECAST MODELS HAVE SLOWED UP THE PROGRESS OF THIS SYSTEM OVER PREVIOUS RUNS...BRINGING THE ASSOCIATED COLD FRONT...ALONG WITH A SLIGHT CHANCE OF SHOWERS/THUNDERSTORMS...INTO WESTERN MONTANA SUNDAY AFTERNOON. SOUTHERLY WINDS WILL INCREASE AHEAD OF THE FRONT ACROSS THE TFX CWA ON SUNDAY. DAYTIME HIGHS THROUGH THE WEEKEND WILL WARM UP TO BETWEEN 15 AND 20 DEGREES ABOVE NORMAL...FOR NEAR RECORD HIGH TEMPERATURES. COULSTON SUNDAY NIGHT THROUGH FRIDAY...MEDIUM RANGE MODELS ARE IN DECENT AGREEMENT TO START THE PERIOD. AN UPPER TROF AND ASSOCIATED SURFACE COLD FRONT WILL MOVE ACROSS THE AREA SUNDAY NIGHT THROUGH MONDAY. ISOLATED THUNDERSTORMS MAY DEVELOP ALONG AND AHEAD OF THE FRONT...BUT THESE WILL BE MAINLY OVER THE ROCKY MOUNTAIN FRONT AND OVER PORTIONS OF SOUTHWEST MONTANA. TEMPERATURES BY MONDAY AFTERNOON WILL BE 12 TO 15 DEGREES COOLER THAN SUNDAY READINGS. ZONAL FLOW ALOFT WILL BECOME ESTABLISHED OVER THE AREA BY MONDAY NIGHT AND THIS WILL BRING GENERALLY DRY AND STABLE CONDITIONS TO THE AREA THROUGH WEDNESDAY. THE EXCEPTION WILL BE THE ROCKY MOUNTAIN FRONT WHERE ISOLATED SHOWERS AND/OR THUNDERSTORMS WILL BE A DAILY POSSIBILITY. SURFACE WINDS WILL BECOME BREEZY MONDAY AND TUESDAY AS THE STRONG WESTERLY FLOW ALOFT MIXES DOWN DURING THE AFTERNOON HOURS. AN UPPER TROF APPROACHES THE WEST COAST THURSDAY ALLOWING FOR AN INCREASING SOUTHWEST FLOW ALOFT OVER THE AREA. MOISTURE WILL BE INCREASINGLY ADVECTED INTO THE AREA BY THE END OF THE PERIOD WITH SHOWERS AND/OR THUNDERSTORMS DEVELOPING OVER SOUTHWEST MONTANA. TEMPERATURES WILL REMAIN 6 TO 8 DEGREES ABOVE SEASONAL AVERAGES THROUGH THE PERIOD. && .PRELIMINARY POINT TEMPS/POPS... GTF 90 54 91 53 / 0 0 0 0 CTB 86 48 91 47 / 0 0 0 0 HLN 88 52 89 50 / 0 0 0 0 BZN 86 44 87 44 / 0 0 0 0 WEY 76 32 77 31 / 0 0 0 0 DLN 84 46 84 46 / 0 0 0 0 HVR 91 48 93 48 / 0 0 0 0 LWT 87 49 88 49 / 0 0 0 0 && .TFX WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING UNTIL MIDNIGHT MDT TONIGHT BLAINE...CENTRAL AND SOUTHERN LEWIS AND CLARK...CHOUTEAU...EASTERN GLACIER...EASTERN PONDERA...EASTERN TETON...HILL...LIBERTY...NORTHERN ROCKY MOUNTAIN FRONT...SOUTHERN ROCKY MOUNTAIN FRONT...TOOLE. HIGH WIND WARNING UNTIL MIDNIGHT MDT TONIGHT FOR ELEVATIONS ABOVE 5000 FEET FOR NORTHERN ROCKY MOUNTAIN FRONT. RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FERGUS. && WEATHER.GOV/GREATFALLS
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE GREAT FALLS MT 437 AM MDT FRI SEP 23 2011 MTZ009-241200- NORTHERN ROCKY MOUNTAIN FRONT- 437 AM MDT FRI SEP 23 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTH CENTRAL MONTANA. .DAY ONE...TODAY AND TONIGHT A RED FLAG WARNING REMAINS IN EFFECT THROUGH THIS EVENING FOR STRONG WINDS AND LOW RELATIVE HUMIDITY FOR FIRE WEATHER ZONES 112...113...AND 114 OF NORTH CENTRAL MONTANA. A HIGH WIND WARNING IS ALSO IN EFFECT THROUGH THIS EVENING FOR ELEVATIONS ABOVE 5000 FEET ALONG THE NORTHERN ROCKY MOUNTAIN FRONT. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS REQUESTED FOR TODAY THROUGH THIS EVENING. REPORTS OF STRONG WINDS OR WIND DAMAGE WOULD BE GREATLY APPRECIATED. MTZ010-011-014-044>049-241200- EASTERN GLACIER-HILL-CENTRAL AND SOUTHERN LEWIS AND CLARK-TOOLE- LIBERTY-EASTERN PONDERA-BLAINE-SOUTHERN ROCKY MOUNTAIN FRONT- EASTERN TETON- 437 AM MDT FRI SEP 23 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTH CENTRAL MONTANA AND SOUTHWEST MONTANA. .DAY ONE...TODAY AND TONIGHT A RED FLAG WARNING REMAINS IN EFFECT THROUGH THIS EVENING FOR STRONG WINDS AND LOW RELATIVE HUMIDITY FOR FIRE WEATHER ZONES 112...113...AND 114 OF NORTH CENTRAL MONTANA. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME. MTZ012-013-050-051-241200- CASCADE-CHOUTEAU-JUDITH BASIN-FERGUS- 437 AM MDT FRI SEP 23 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL MONTANA AND NORTH CENTRAL MONTANA. .DAY ONE...TODAY AND TONIGHT VERY WARM AND DRY CONDITIONS ARE EXPECTED ACROSS CENTRAL MONTANA AGAIN TODAY...ALONG WITH BREEZY WESTERLY WINDS. THIS MAY CREATE CRITICAL FIRE WEATHER CONDITIONS...AND THE SITUATION WILL CONTINUE TO BE MONITORED THROUGHOUT THE DAY FOR POSSIBLE FIRE WEATHER HIGHLIGHTS. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME. MTZ008-015-052>055-241200- BEAVERHEAD-MADISON-JEFFERSON-BROADWATER-MEAGHER-GALLATIN- 437 AM MDT FRI SEP 23 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHWEST MONTANA. .DAY ONE...TODAY AND TONIGHT THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.
3 high wind. Local standard time, as filed.
A wind gust to 74 mph was reported at Saint Mary 13W (the Logan Pass Visitor Center in Glacier National Park).
A wind gust to 64 mph was reported at East Glacier Park 8SE (the Deep Creek RAWS site).
A wind gust to 58 mph was reported at Heart Butte 1NW.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Montana in 2011Every state in 2011This day in weather historyWarnings in Montana, September 2011
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: 346373, 346374, 346375.