A rush of arctic air following a storm system brought wind chills to -40F or colder in some areas.
Every event with a place to put it; 4 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
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 GGW wrote it up.
A rush of arctic air following a storm system brought wind chills to -40F or colder in some areas.
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 Glasgow, MT wrote its last area forecast discussion before the first event at Feb 7, 9:05 PM MST, 55 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GLASGOW MT 905 PM MST MON FEB 7 2011 .SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH WEDNESDAY... TEMPERATURES ACROSS THE REGION LOOK TO BE ON TRACK IN FALLING AS A HIGH PRESSURE CENTER MOVES THROUGH THE NORTHEASTERN SECTION OF THE CWA. CLOUD COVER HAS CLEARED FROM ALL AREAS EXCEPT THE FAR SOUTHWEST. HARD PART TONIGHT WILL BE DETERMINING WHETHER THE NORTHEAST OR NORTHWEST PORTION OF THE CWA WILL BE THE COLDER SPOT. PREVIOUS FORECASTED LOWS PLACED LOWEST TEMPS ACROSS NORTHWEST CWA DUE TO THE USUAL CLIMATIC LOW THAT OCCURS ALONG NORTHERN PHILLIPS COUNTY INTO THE MILK RIVER VALLEY... HOWEVER THERE ARE SOME INDICATORS WITH CURRENT LOWEST TEMPERATURES IN THE NORTHEAST QUADRANT OF THE SURFACE HIGH PRESSURE OVER SOUTHEASTERN SASKATCHEWAN THAT POINT TOWARD THE NORTHEASTERN SECTION OF THE CWA HAVING THE STRONGEST RADIATIONAL COOLING. GAH PREVIOUS SHORT TERM DISCUSSION... UPDATED THE FORECAST TO DROP THE WINTER STORM WARNING AND THE WINTER WEATHER ADVISORY ACROSS THE REGION. THE FOLLOWING COUNTIES ARE UNDER A WIND CHILL ADVISORY FOR TONIGHT THROUGH TUESDAY MORNING...WIBAUX...PRAIRIE...PETROLEUM AND SOUTHWEST PHILLIPS. THE REST OF THE ZONES ACROSS NORTHEAST MONTANA ARE UNDER A WIND CHILL WARNING THROUGH TUESDAY MORNING. RSMITH WINTER STORM CONTINUES THIS AFTERNOON ALTHOUGH SNOW IS BEGINNING TO DISSIPATE ACROSS THE SOUTHWESTERN ZONES AND AT THIS POINT IT LOOKS LIKE WE WILL BE ABLE TO END THE WINTER WEATHER ADVISORY AND THE WINTER STORM WARNING AT 6 PM THIS EVENING. TEMPERATURES WILL CONTINUE TO DROP OFF THIS EVENING AND WE WILL SEE THE CLOUDS START TO DISSIPATE AS WELL FROM NORTH TO SOUTH. MONDAY NIGHT INTO TUESDAY...AN ARCTIC SURFACE HIGH SLIDE DOWN ACROSS THE REGION FROM THE NORTHWEST. SKY COVER WILL ALL BUT DISAPPEAR LATE THIS EVENING ACROSS MOST OF THE CWA WITH THE SOUTHWESTERN ZONES BEING THE ONLY EXCEPTION. THE WINDS ARE THE KEY ISSUE FOR TONIGHT AND TOMORROW MORNING AND FOR THE MOST PART THEY WILL REMAIN BETWEEN 8 AND 12 MPH...ALTHOUGH OCCASIONALLY DROPPING BELOW 8 MPH. 850 MB TEMPERATURES WILL DROP TO BETWEEN -14*C AND -17*C AND WILL COMBINE WITH THICKNESS VALUES OF 507 DM AND THE EXISTING SNOW PACK...SO EXPECT A VERY COLD START TUESDAY WITH LOWS RANGING FROM -20 IN WIBAUX COUNTY TO -33 IN NORTHERN PHILLIPS. TEMPERATURES WILL STRUGGLING TO CLIMB ABOVE ZERO NORTH OF THE MISSOURI RIVER AND WILL ONLY MAKE INTO INTO THE SINGLE DIGITS ABOVE SOUTH OF THE MISSOURI RIVER. SO WITH THE WIND AND THE EXTREME COLD IN MIND HAVE EXTENDED THE WIND CHILL ADVISORY AND ALSO LAUNCHED A WIND CHILL WARNING. THE ADVISORY COVERS WIBAUX...PRAIRIE...PETROLEUM AND SOUTHWEST PHILLIPS COUNTIES. THE WIND CHILL WARNING IS FOR ALL OTHER COUNTIES AND WIND CHILL READINGS ACROSS THE REGION WILL RANGE BETWEEN -20 AND -50 OVERNIGHT. BOTH THE WIND CHILL WARNING AND ADVISORY WILL GO FROM THIS EVENING UNTIL NOON TUESDAY. TUESDAY NIGHT WE WILL LIKELY NEED ANOTHER WIND CHILL ADVISORY AND WEDNESDAY SHOULD BE SLIGHTLY WARMER AS CHINOOK WINDS FROM THE WEST TRY TO MIX OUT THE SHALLOW COLD ARCTIC AIR OVER THE REGION. WHICH MEANS HIGHS ON WEDNESDAY WILL BE IN THE TEENS ABOVE ZERO. RSMITH .LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY... NO MAJOR CHANGES TO THE EXTENDED PERIOD. MODELS STILL MOSTLY DRY WITH A WARMING TREND FOR MOST OF THE PERIOD WITH UPPER RIDGE MOVING INLAND. RIDGE GETS KNOCKED DOWN LATE IN THE WEEKEND WHICH SHOULD RESULT IN A LITTLE COLDER TEMPERATURES FOR EARLY NEXT WEEK. EBERT PREVIOUS LONG TERM DISCUSSION...WILL SEE DRY WEATHER FOR MOST OF THE PERIOD WITH A WARMING TREND. NORTHWEST FLOW ALOFT ON THURSDAY WILL BE FOLLOWED BY AN UPPER RIDGE THAT MOVES INLAND FROM THE PACIFIC AND FLATTENS SOMEWHAT BY THE TIME IT REACHES MONTANA BY THE END OF THE WEEK. SHALLOW ARCTIC AIRMASS WILL GET PUSHED TO THE EAST BY A WARM FRONT ON THURSDAY. TEMPERATURES WILL WARM TO NEAR TO ABOVE NORMAL FOR THE REMAINDER OF THE PERIOD. THE MODELS ONLY BRING ENOUGH MOISTURE WITH THE WARM FRONT ON THURSDAY TO PRODUCE MOSTLY CLOUDY SKIES. MODELS ARE IN DECENT AGREEMENT WITH THE OVERALL PATTERN. WITH THE UPPER RIDGE OVER THE AREA FRIDAY AND SATURDAY...MOST AREAS WILL SEE ABOVE FREEZING TEMPERATURES FOR HIGHS BY SATURDAY. A SHORTWAVE TROUGH MOVING THROUGH ALBERTA AND SASKATCHEWAN WILL BRING A MAINLY DRY COLD FRONT THROUGH THE AREA ON SUNDAY. SLIGHTLY COOLER TEMPERATURES WILL FOLLOW ON MONDAY. FORRESTER && .AVIATION... VFR. HIGH CLOUDS WILL CONTINUE TO DIMINISH ACROSS THE REGION TONIGHT. ONLY PROBLEM POSSIBLE WOULD BE SETTLEMENT ICE FOG DURING THE EARLY MORNING HOURS. PROTON && .GLASGOW WATCHES/WARNINGS/ADVISORIES... WIND CHILL WARNING UNTIL 11 AM MST TUESDAY FOR CENTRAL AND SOUTHEAST PHILLIPS...CENTRAL AND SOUTHERN VALLEY...DANIELS... SHERIDAN...WESTERN ROOSEVELT...GARFIELD...MCCONE...RICHLAND... DAWSON...NORTHERN PHILLIPS...NORTHERN VALLEY...EASTERN ROOSEVELT. WIND CHILL ADVISORY UNTIL 11 AM MST TUESDAY FOR PETROLEUM... PRAIRIE...WIBAUX...SOUTHWEST PHILLIPS. && WEATHER.GOV/GLASGOW
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE GLASGOW MT 528 PM MST MON FEB 7 2011 MTZ021-026-027-060-081200- PETROLEUM-PRAIRIE-WIBAUX-SOUTHWEST PHILLIPS- 528 PM MST MON FEB 7 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHEAST MONTANA. .DAY ONE...TONIGHT WIND CHILL ADVISORY IS IN EFFECT DUE TO A COMBINATION OF BELOW ZERO TEMPERATURES AND SUSTAINED WIND SPEED OF 8 TO 12 MPH. WIND CHILLS OF 20 BELOW TO 30 BELOW CAN ALSO BE ANTICIPATED. A SMALL STREAM FLOOD ADVISORY IS IN EFFECT FOR THE MUSSELLSHELL RIVER UNTIL 10 PM THIS AFTERNOON. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY DANGEROUS ARCTIC COLD WILL IMPACT THE REGION THROUGH WEDNESDAY MORNING WITH WIND CHILLS OF 20 TO 40 BELOW POSSIBLE. TEMPERATURES ARE THEN EXPECTED TO BEGIN A WARMING TREND LATE IN THE WEEK. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. MTZ016>020-022>025-059-061-062-081200- CENTRAL AND SOUTHEAST PHILLIPS-CENTRAL AND SOUTHERN VALLEY- DANIELS-SHERIDAN-WESTERN ROOSEVELT-GARFIELD-MCCONE-RICHLAND- DAWSON-NORTHERN PHILLIPS-NORTHERN VALLEY-EASTERN ROOSEVELT- 528 PM MST MON FEB 7 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHEAST MONTANA. .DAY ONE...TONIGHT A WIND CHILL WARNING IS IN EFFECT TONIGHT THROUGH TUESDAY MORNING. TEMPERATURES WELL BELOW ZERO WILL COMBINE WITH SUSTAINED 8 TO 12 MPH WIND TO PRODUCE WIND CHILL OF 35 TO 50 BELOW ZERO BY TUESDAY MORNING. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY DANGEROUS ARCTIC COLD WILL IMPACT THE REGION THROUGH WEDNESDAY MORNING WITH WIND CHILLS OF 30 TO 50 BELOW POSSIBLE. TEMPERATURES ARE THEN EXPECTED TO BEGIN A WARMING TREND LATE IN THE WEEK. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GLASGOW MT
502 PM MST MON FEB 07 2011
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0500 PM SNOW 6 NE FLATWILLOW 46.89N 108.31W
02/07/2011 E4.0 INCH PETROLEUM MT TRAINED SPOTTER
STARTED LATE SUNDAY NIGHT. ENDED 4 PM TODAY.
&&
BBPRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE GLASGOW MT
514 PM MST MON FEB 07 2011
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0812 AM SNOW ZORTMAN 47.92N 108.53W
02/07/2011 E3.0 INCH PHILLIPS MT TRAINED SPOTTER
SNOW STARTED SUNDAY NIGHT
0835 AM SNOW WINNETT 47.00N 108.35W
02/07/2011 E2.0 INCH PETROLEUM MT TRAINED SPOTTER
SOME DRIFTING. SNOW STARTED SUNDAY NIGHT.
0840 AM SNOW FLATWILLOW 46.83N 108.40W
02/07/2011 E3.0 INCH PETROLEUM MT TRAINED SPOTTER
SNOW STARTED SUNDAY EVENING
0841 AM SNOW 23 SW MALTA 48.12N 108.23W
02/07/2011 E2.0 INCH PHILLIPS MT TRAINED SPOTTER
GUSTS OF 30 TO 35 MPH. LOTS OF DRIFTING. SNOW STARTED
SUNDAY NIGHT.
0845 AM SNOW 20 E WINNETT 47.00N 107.93W
02/07/2011 E3.0 INCH PETROLEUM MT TRAINED SPOTTER
SNOW STARTED SUNDAY NIGHT
0846 AM SNOW 15 ESE SAND SPRINGS 47.02N 107.19W
02/07/2011 E2.0 INCH GARFIELD MT TRAINED SPOTTER
LOTS OF DRIFTING. SNOW STARTED AROUND MIDNIGHT SUNDAY
NIGHT.
0940 AM SNOW WINNETT 47.00N 108.35W
02/07/2011 E4.0 INCH PETROLEUM MT LAW ENFORCEMENT
LOTS OF DRIFTING
1217 PM SNOW 8 SW ZORTMAN 47.84N 108.65W
02/07/2011 E3.0 INCH PHILLIPS MT TRAINED SPOTTER
LOTS OF DRIFTING
1219 PM SNOW 18 N WINNETT 47.26N 108.35W
02/07/2011 E3.0 INCH PETROLEUM MT TRAINED SPOTTER
LOTS OF DRIFTING
0200 PM HEAVY SNOW ZORTMAN 47.92N 108.53W
02/07/2011 E6.0 INCH PHILLIPS MT TRAINED SPOTTER
SOME DRIFTING. SNOW STARTED SUNDAY NIGHT AND ENDED AROUND
2 PM TODAY.
0243 PM SNOW 4 E WINNETT 47.00N 108.27W
02/07/2011 E3.0 INCH PETROLEUM MT TRAINED SPOTTER
SOME DRIFTING
0259 PM HEAVY SNOW WINNETT 47.00N 108.35W
02/07/2011 E6.0 INCH PETROLEUM MT LAW ENFORCEMENT
SNOW STILL FALLING. LOTS OF DRIFTING WITH LOW VISIBILITY.
0500 PM SNOW 6 NE FLATWILLOW 46.89N 108.31W
02/07/2011 E4.0 INCH PETROLEUM MT TRAINED SPOTTER
STARTED LATE SUNDAY NIGHT. ENDED 4 PM TODAY.
&&
BBThe national radar mosaic for the moment the first event began.
4 extreme cold/wind chill. Local standard time, as filed.
Coronach, Saskatchewan observations and Navajo Davis unit reported wind chills of -41 and -40 respectively for two hours or more.
Wind chills to -48 were recorded. Wind chills of -40F or colder occurred for two hours or more.
Windchills of -40F occurred for two hours.
Several stations reported wind chills of -40F or colder. Medicine Lake had the coldest with -47F.
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, February 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: 284448, 284450, 284451, 284449.