Strong westerly winds aloft produced high winds along the Rocky Mountain front. Wind gusts in excess of 80 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.
Strong westerly winds aloft produced high winds along the Rocky Mountain front. Wind gusts in excess of 80 mph were reported. The high winds rolled a semi-tractor trailer on U.S. Highway 89.
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 Jan 20, 4:45 AM MST, 1 hour earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREAT FALLS MT 445 AM MST THU JAN 20 2011 ...UPDATE TO AVIATION... .DISCUSSION... TODAY THROUGH SATURDAY...MOIST NORTHWEST FLOW ALOFT WILL PERSIST OVER THE FORECAST AREA THROUGH THE SHORT TERM PERIOD. AT THE SURFACE...A LOW PRESSURE TROUGH CONTINUES TO DEVELOP ACROSS NORTH CENTRAL MONTANA. THIS FEATURE WILL CAUSE STRONG DOWNSLOPE PRESSURE GRADIENTS ALONG THE EAST SLOPES OF THE ROCKY MOUNTAINS THIS AFTERNOON AND EVENING. IN ADDITION...MID LEVEL WINDS INCREASE SUBSTANTIALLY TODAY AND WILL ACCELERATE THE DOWNSLOPE COMPONENT OF THE WIND ALONG THE ROCKY MOUNTAIN FRONT AND OVER THE ADJACENT PLAINS. HAVE EXPANDED THE HIGH WIND WARNING TO INCLUDE TOOLE... EASTERN PONDERA AND NORTHERN PORTIONS OF CENTRAL LEWIS AND CLARK COUNTY. WINDS WILL ALSO INCREASE OVER THE PLAINS BUT IT DOES NOT APPEAR THAT THERE WILL BE WIDESPREAD HIGH WINDS ACROSS CENTRAL MONTANA SO HAVE CANCELLED THE REMAINING PORTIONS OF THE HIGH WIND WATCH. MODELS INDICATE THAT THE STRONG WINDS WILL DIMINISH QUICKLY OVERNIGHT WITH SCATTERED SNOW SHOWERS SPREADING ACROSS THE REGION BEFORE ANOTHER DRY SLOT MOVES ACROSS THE AREA ON FRIDAY. BY FRIDAY NIGHT AN UPPER LEVEL SHORTWAVE EMBEDDED IN THE NORTHWEST FLOW ALOFT WILL SLIDE ACROSS THE NORTHERN ROCKY MOUNTAINS BRINGING AN INCREASING LIKELIHOOD OF WIDESPREAD SNOW TO THE FORECAST AREA. AT THIS TIME THE SYSTEM DOES NOT LOOK VERY STRONG BUT CAN NOT RULE OUT THAT SOME PORTIONS OF THE FORECAST AREA MAY REQUIRE A WINTER WEATHER ADVISORY FRIDAY NIGHT. TEMPERATURES THROUGH THE SHORT TERM PERIOD ARE EXPECTED TO REMAIN NEAR OR BELOW SEASONAL NORMALS. MPJ SATURDAY NIGHT THROUGH THURSDAY NIGHT...AN UPPER LEVEL RIDGE OF HIGH PRESSURE WILL REMAIN JUST OFF THE PACIFIC COAST FROM SATURDAY NIGHT THROUGH TUESDAY. WEAK DISTURBANCES IN THE RESULTING NORTHWEST FLOW ALOFT WILL KEEP AT LEAST A CHANCE OF SNOW IN THE MOUNTAINS...WHILE BREEZY WESTERLY SURFACE WINDS WILL GENERALLY LIMIT THE CHANCE FOR PRECIPITATION OVER THE PLAINS. HOWEVER...A MORE ORGANIZED SHORTWAVE TROUGH WILL MOVE THROUGH MONTANA SUNDAY AND SUNDAY NIGHT WITH A CANADIAN COLD FRONT...BRINGING A SLIGHT CHANCE OF PRECIPITATION TO THE PLAINS/VALLEYS OF THE TFX CWA AS WELL. FOR TUESDAY NIGHT THROUGH THURSDAY NIGHT...THE UPPER LEVEL RIDGE WILL GRADUALLY MOVE EAST INTO THE PACIFIC COAST STATES...GENERALLY DRYING OUT THE RESULTING MORE STABLE WEST-NORTHWEST FLOW ALOFT. THIS WILL KEEP ONLY A SLIGHT CHANCE OF PRECIPITATION IN THE MOUNTAINS...WHILE THE REMAINDER OF THE CWA WILL REMAIN DRY. TEMPERATURES WILL MOSTLY REMAIN NEAR TO SLIGHTLY ABOVE NORMAL GENERALLY DUE TO INCREASED CLOUDINESS OVERNIGHT AND TO THE BREEZY WESTERLY WINDS OVER THE PLAINS. COULSTON && .AVIATION... UPDATED 1145Z. VFR CONDITIONS WILL CONTINUE ACROSS NORTH CENTRAL...CENTRAL...AND SOUTHWEST MONTANA THROUGH AT LEAST 12Z FRIDAY. A DISTURBANCE IN THE NORTHWEST FLOW ALOFT WILL MOVE THROUGH THE AREA DURING THE PERIOD. THE MAIN IMPACTS FROM THIS DISTURBANCE WILL BE PRECIPITATION OBSCURING MAINLY MOUNTAIN TOPS...WHILE STRONG/GUSTY WESTERLY DOWNSLOPE WINDS WILL KEEP MOST LOWER ELEVATIONS DRY. THE PRECIPITATION WILL DEVELOP IN THE MOUNTAINS THROUGH 18Z AS THE DISTURBANCE APPROACHES THE AREA...BE MOST WIDESPREAD BETWEEN 18Z AND 06Z...THEN DECREASE AFTER 06Z AS THE DISTURBANCE EXITS THE AREA. WINDS WILL ALSO INCREASE GENERALLY THROUGH 20Z...BE STRONGEST BETWEEN 20Z AND 03Z...THEN DECREASE AFTER 03Z. MOST TERMINALS WILL EXPERIENCE GUSTY WINDS TO A CERTAIN EXTENT...BUT THE STRONGEST WINDS WILL BE ALONG THE ROCKY MOUNTAIN FRONT AND OUT TO A KCTB-KGTF-KLWT LINE. WINDS CLOSEST TO THE FRONT RANGE WILL GUST TO NEAR 70 KT...WHILE CLOSER TO THE AFOREMENTIONED LINE WINDS WILL MOSTLY GUST TO NEAR 45 KT. THE BEST CHANCES FOR PRECIPITATION WITH POSSIBLE MVFR CEILINGS AT ANY TERMINALS (ALTHOUGH IT IS STILL LOW) WILL BE AT KHVR...KHLN...AND KBZN...WHICH WILL BE OUT OF THE STRONGEST DOWNSLOPE WINDS. COULSTON && .PRELIMINARY POINT TEMPS/POPS... GTF 37 26 38 24 / 10 20 10 60 CTB 35 22 37 21 / 10 20 10 50 HLN 33 25 40 29 / 10 20 10 50 BZN 32 23 37 32 / 20 30 20 60 WEY 20 14 25 18 / 20 40 50 80 DLN 30 24 38 27 / 10 20 20 50 HVR 25 19 26 23 / 10 20 10 60 LWT 34 26 37 25 / 10 30 10 60 && .TFX WATCHES/WARNINGS/ADVISORIES... HIGH WIND WARNING FROM 8 AM THIS MORNING TO 11 PM MST THIS EVENING EASTERN GLACIER...NORTHERN ROCKY MOUNTAIN FRONT... SOUTHERN ROCKY MOUNTAIN FRONT. HIGH WIND WARNING FROM 11 AM THIS MORNING TO 11 PM MST THIS EVENING CENTRAL AND SOUTHERN LEWIS AND CLARK...EASTERN PONDERA... TOOLE. && SHORT TERM...MPJ LONG TERM...COULSTON AVIATION...COULSTON WEATHER.GOV/GREATFALLS
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE GREAT FALLS MT 415 AM MST THU JAN 20 2011 MTZ009-010-014-044-046-048-211200- NORTHERN ROCKY MOUNTAIN FRONT-EASTERN GLACIER- CENTRAL AND SOUTHERN LEWIS AND CLARK-TOOLE-EASTERN PONDERA- SOUTHERN ROCKY MOUNTAIN FRONT- 415 AM MST THU JAN 20 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTH CENTRAL MONTANA AND SOUTHWEST MONTANA. .DAY ONE...TODAY AND TONIGHT A HIGH WIND WARNING IS IN EFFECT TODAY THROUGH LATE THIS EVENING. WINDS WILL INCREASE ACROSS THE REGION BECOMING 30 TO 50 MPH WITH GUSTS UP TO 80 MPH POSSIBLE THROUGH FAVORED CANYONS AND PASSES. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY A PACIFIC STORM SYSTEM WILL MOVE THROUGH THE REGION FRIDAY NIGHT AND IS EXPECTED TO BRING WIDESPREAD SNOW. IT IS POSSIBLE THAT WINTER WEATHER HIGHLIGHTS COULD BE ISSUED FOR PORTIONS OF THE FORECAST AREA. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. MTZ008-011>013-015-045-047-049>055-211200- BEAVERHEAD-HILL-CASCADE-CHOUTEAU-MADISON-LIBERTY-BLAINE- EASTERN TETON-JUDITH BASIN-FERGUS-JEFFERSON-BROADWATER-MEAGHER- GALLATIN- 415 AM MST THU JAN 20 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL MONTANA...NORTH CENTRAL MONTANA AND SOUTHWEST MONTANA. .DAY ONE...TODAY AND TONIGHT GUSTY SOUTHWEST TO WEST WINDS WILL INCREASE ACROSS THE FORECAST AREA TODAY AND ARE EXPECTED TO CONTINUE THROUGH LATE EVENING. ISOLATED WIND GUSTS IN FAVORED LOCATIONS MAY APPROACH OR EXCEED 55 MPH AT TIMES. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY A PACIFIC STORM SYSTEM WILL MOVE THROUGH THE REGION FRIDAY NIGHT AND IS EXPECTED TO BRING WIDESPREAD SNOW. IT IS POSSIBLE THAT WINTER WEATHER HIGHLIGHTS COULD BE ISSUED FOR PORTIONS OF THE FORECAST AREA. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.
6 high wind. Local standard time, as filed.
A wind gust to 58 mph was reported at East Glacier Park 1E (the Two Medicine DOT site).
A wind gust to 68 mph was reported at Bynum 13W (the Dellwo MSCN site).
A gust to 60 mph was reported at the Cut Bank ASOS site.
Sustained winds of 43 mph were reported for over an hour at Sunburst 6NNW.
A wind gust to 67 mph was reported at Choteau 1NE.
A wind gust to 63 mph was reported at Pendroy 2NW (the DOT 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, January 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: 278438, 278455, 278439, 278441, 278456, 278453.