Strong westerly flow aloft and the passage of an upper trough brought high winds to a large portionof Northcentral and Southwest Montana. Wind gusts in excess of 65 mph were common.
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.
Strong westerly flow aloft and the passage of an upper trough brought high winds to a large portionof Northcentral and Southwest Montana. Wind gusts in excess of 65 mph were common.
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 Nov 21, 5:00 PM MST, 2 hours earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREAT FALLS MT 500 PM MST MON NOV 21 2011 ...UPDATE TO AVIATION... .DISCUSSION... TONIGHT THROUGH WEDNESDAY...NOT MUCH CHANGE TO THE OVERALL FORECAST THIS AFTERNOON. THE HELENA VALLEY HAS BEEN SLOW TO WARM UP TODAY...BUT THE VALLEY SHOULD START TO SLOWLY WARM UP THIS EVENING AS WINDS MIX DOWN THE WARMER AIR ALOFT. OTHERWISE...THE WARMER AIR HAS PUSHED NORTHWARD INTO THE HAVRE AND HARLEM AREAS AS WELL. RAIN/MOUNTAIN SNOW IS DEVELOPING OVER THE FRONT RANGE OF THE ROCKIES. THE PRECIPITATION SHOULD BE LIGHT TONIGHT...AND THEN PICK UP IN INTENSITY A BIT ON TUESDAY. THE WINTER STORM WATCH WILL CONTINUE...AS MODELS CONTINUE TO BE A BIT UNCERTAIN ON HOW MUCH SNOW IS GOING TO FALL ABOVE 5000 FEET. THE HIGH WIND WARNING FOR TONIGHT LOOKS GOOD OVER THE FRONT RANGE AS WELL. THE HIGH WIND WATCH FOR THE CUT BANK AREA WILL REMAIN A WATCH AT THIS TIME. LATEST MODELS NOW HAVE WINDS JUST BELOW/NEAR WARNING CRITERIA...THUS WE WILL HOLD OFF FOR NOW ON UPGRADING THIS AREA TO A WARNING. IN TERMS OF TEMPERATURES ACROSS THE REGION FOR TUESDAY AND WEDNESDAY...EXPECT TEMPERATURES TO GENERALLY BE ABOVE NORMAL FOR MOST AREAS...EXPECT THE ROCKY MOUNTAIN FRONT. BY WEDNESDAY...AFTERNOON TEMPERATURES COULD AVERAGE BETWEEN 10 AND 15 DEGREES ABOVE NORMAL. PRECIPITATION CHANCES LOOK VERY LOW OVER THE PLAINS AND THE VALLEYS OF THE SOUTHWEST TONIGHT THROUGH WEDNESDAY AS WELL...BECAUSE OF THE BRISK WESTERLY FLOW ALOFT RESULTING IN DOWNSLOPE CONDITIONS AWAY FROM THE FRONT RANGE OF THE ROCKIES. BRUSDA WEDNESDAY NIGHT THROUGH MONDAY NIGHT...A FAST SW FLOW ALOFT AHEAD OF AN OFFSHORE UPPER LEVEL TROUGH TRANSITIONS TO WESTERLY FLOW BY THANKSGIVING DAY AS PACIFIC ENERGY MOVES ONSHORE. ENERGY INITIALLY ASSOCIATED WITH THE TROUGH IS FAIRLY WEAK AND WILL MAINLY JUST BRING SOME SLIGHT COOLING WITH SNOW SHOWERS GENERALLY CONFINED TO THE WESTERN MTNS THURSDAY. A SOMEWHAT STRONGER WAVE MOVES ACROSS THE AREA THURSDAY NIGHT AND FRIDAY...BRINGING ADDITIONAL COOLING AND A SOMEWHAT BETTER CHANCE FOR SNOW SHOWERS FARTHER EAST ACROSS THE AREA. AN UPPER LEVEL RIDGE THEN REBUILDS OVER THE REGION THIS WEEKEND...BRINGING MILDER TEMPS AND INCREASING WINDS BEFORE THE NEXT UPPER LEVEL SYSTEM DROPS INTO THE AREA FROM THE NW BY EARLY NEXT WEEK. HOENISCH && .AVIATION... UPDATED 00Z. WESTERLY FLOW ALOFT WILL INCREASE THROUGH THE TAF PERIOD. VFR CONDITIONS WILL DOMINATE AT ALL TAF SITES FOR THE TAF PERIOD. WINDS WILL BE STRONGEST TOWARDS THE END OF THE TAF PERIOD ESPECIALLY ALONG THE ROCKY MOUNTAIN FRONT AND ADJACENT HIGH PLAINS. SUK && .PRELIMINARY POINT TEMPS/POPS... GTF 29 49 37 55 / 0 0 0 0 CTB 25 47 36 52 / 0 0 0 0 HLN 20 47 30 49 / 0 0 0 0 BZN 20 44 23 48 / 0 0 0 0 WEY 20 34 20 39 / 40 40 20 0 DLN 19 42 26 46 / 10 10 0 0 HVR 25 48 33 55 / 0 0 0 0 LWT 25 46 32 52 / 0 0 0 0 && .TFX WATCHES/WARNINGS/ADVISORIES... HIGH WIND WATCH FROM TUESDAY MORNING THROUGH WEDNESDAY MORNING EASTERN GLACIER. HIGH WIND WARNING UNTIL 10 PM MST WEDNESDAY NORTHERN ROCKY MOUNTAIN FRONT...SOUTHERN ROCKY MOUNTAIN FRONT. WINTER STORM WATCH FROM LATE TONIGHT THROUGH WEDNESDAY MORNING FOR ELEVATIONS ABOVE 5000 FEET FOR NORTHERN ROCKY MOUNTAIN FRONT. && WEATHER.GOV/GREATFALLS
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE GREAT FALLS MT 509 AM MST MON NOV 21 2011 MTZ009-221300- NORTHERN ROCKY MOUNTAIN FRONT- 509 AM MST MON NOV 21 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTH CENTRAL MONTANA. .DAY ONE...TODAY AND TONIGHT A HIGH WIND WARNING HAS BEEN ISSUED FOR LATE THIS AFTERNOON AND TONIGHT. STRONG WINDS WILL DEVELOP ALONG THE ROCKY MOUNTAIN FRONT AND CONTINUE OVERNIGHT. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY THE HIGH WIND WARNING REMAINS IN EFFECT THROUGH AT LEAST WEDNESDAY EVENING. WINDS WILL DIMINISH SOMEWHAT TUESDAY MORNING BUT WILL BECOME VERY STRONG TUESDAY AFTERNOON AND CONTINUE THROUGH AT LEAST WEDNESDAY EVENING. A WINTER STORM WATCH FOR ELEVATIONS ABOVE 5000 FEET HAS BEEN ISSUED FOR EARLY TUESDAY MORNING THROUGH LATE WEDNESDAY MORNING. HEAVY MOUNTAIN SNOW AND BLOWING SNOW ARE ANTICIPATED. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS REQUIRED FOR LATE THIS AFTERNOON THROUGH WEDNESDAY EVENING. REPORTS OF STRONG WINDS...WIND DAMAGE...HEAVY SNOW ACCUMULATION AND REDUCED VISIBILITY WOULD BE GREATLY APPRECIATED. MTZ048-221300- SOUTHERN ROCKY MOUNTAIN FRONT- 509 AM MST MON NOV 21 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTH CENTRAL MONTANA. .DAY ONE...TODAY AND TONIGHT A HIGH WIND WARNING HAS BEEN ISSUED FOR LATE THIS AFTERNOON AND TONIGHT. STRONG WINDS WILL DEVELOP ALONG THE ROCKY MOUNTAIN FRONT AND CONTINUE OVERNIGHT. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY THE HIGH WIND WARNING REMAINS IN EFFECT THROUGH AT LEAST WEDNESDAY EVENING. WINDS WILL DIMINISH SOMEWHAT TUESDAY MORNING BUT WILL BECOME VERY STRONG TUESDAY AFTERNOON AND CONTINUE THROUGH AT LEAST WEDNESDAY EVENING. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS REQUIRED FOR LATE THIS AFTERNOON THROUGH WEDNESDAY EVENING. REPORTS OF STRONG WINDS AND WIND DAMAGE WOULD BE GREATLY APPRECIATED. MTZ010-221300- EASTERN GLACIER- 509 AM MST MON NOV 21 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTH CENTRAL MONTANA. .DAY ONE...TODAY AND TONIGHT THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER TODAY AND TONIGHT IS LOW. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY A HIGH WIND WATCH REMAINS IN EFFECT FOR LATE TUESDAY MORNING THROUGH WEDNESDAY MORNING. SUSTAINED HIGH WINDS ARE EXPECTED TO DEVELOP ACROSS EASTERN GLACIER COUNTY LATE TUESDAY MORNING AND CONTINUE THROUGH WEDNESDAY MORNING. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION COULD BE REQUIRED FOR STRONG WINDS LATE TUESDAY MORNING THROUGH WEDNESDAY MORNING. MTZ008-011>015-044>047-049>055-221300- BEAVERHEAD-HILL-CASCADE-CHOUTEAU- CENTRAL AND SOUTHERN LEWIS AND CLARK-MADISON-TOOLE-LIBERTY- EASTERN PONDERA-BLAINE-EASTERN TETON-JUDITH BASIN-FERGUS- JEFFERSON-BROADWATER-MEAGHER-GALLATIN- 509 AM MST MON NOV 21 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL MONTANA...NORTH CENTRAL MONTANA AND SOUTHWEST MONTANA. .DAY ONE...TODAY AND TONIGHT THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.
9 high wind. Local standard time, as filed.
A wind gust to 75 mph was reported at Bynum 14W (the Dellwo MSCN site).
Sustained wind speeds of 40 mph or greater were reported at McAllister 4NNE (the Norris Hill DOT site) for several hours.
A wind gust to 58 mph was reported at Hilger 7SE (the Judith Peak RAWS site).
A wind gust to 65 mph was reported at Sunburst 6NNW (the Sweetgrass DOT site).
A wind gust to 59 mph was reported at White Sulphur Springs 1SE (the White Sulphur Springs RAWS site).
A wind gust to 64 mph was reported at the Havre ASOS site.
A wind gust to 77 mph was reported at Cascade 1W.
A wind gust to 83 mph was reported at Dutton 4NNE.
A wind gust to 67 mph was reported at the Cut Bank ASOS site.
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, November 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: 352229, 352227, 352231, 352228, 352232, 352222, 352224, 352230, 352220.