A developing low pressure system approaching from the south and bringing pacific moisture interacted with a cold Canadian air mass approaching from the south to produce the first winter storm of the season over northeast Montana.
Every event with a place to put it; 16 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 developing low pressure system approaching from the south and bringing pacific moisture interacted with a cold Canadian air mass approaching from the south to produce the first winter storm of the season over northeast Montana.
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 Nov 5, 3:41 AM MST, 1 hour 19 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GLASGOW MT 441 AM MDT SAT NOV 5 2011 .SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH MONDAY... MAIN PROBLEM TODAY IS THE FIRST MAJOR WINTER WEATHER EVENT OF THE 2011-2012 WINTER SEASON. A STRONG SHORTWAVE BEING PUSHED BY A STRONG UPPER LEVEL JET CORE WILL ROUND THE BASE OF A DEEP UPPER TROUGH ACROSS THE SOUTHWESTERN US. THIS SHORTWAVE WILL HEAD STRAIGHT FOR EASTERN MONTANA AND WESTERN NORTH DAKOTA TODAY AND BECOME VERTICALLY STACKED OVER MANITOBA BY SUNDAY AFTERNOON. JUST AHEAD OF THE JET CORE AND SHORTWAVE IS AN 700 MB MOISTURE PLUME COMING FROM THE PACIFIC. SURFACE LOW IS ANTICIPATED TO DEEPEN AND FORM A COLD FRONT DIRECTLY BEHIND IT WHICH SHOULD PASS THROUGH THE GGW CWA BETWEEN 6AM AND NOON. BEHIND THIS FRONT DIURNAL TEMPERATURES WILL STALL THROUGH THE DAY DUE TO STRONG CAA. 850MB TO 500 MB FRONTOGENESIS REALLY GETS GOING ACROSS EASTERN MONTANA AS THE 700MB LOW BEGINS TO DEEPEN...SO THE BEST QG FORCING IS ALONG THIS ZONE. THIS WILL HAPPEN LATE THIS AFTERNOON AND EARLY THIS EVENING. DEFINITELY HAD A TOUGH TIME WITH THIS STORM BECAUSE THE MODELS CHANGES ONCE AGAIN. THE 00Z RUN OF THE GFS STRENGTHENED TO MATCH THE PREVIOUS 18Z NAM. THE 00Z NAM PRETTY MUCH STAYED CONSISTENT WITH ITS PREVIOUS RUN. THE 00Z ECMWF CAME IN STRONG LIKE THE 00Z GFS. THIS CAUSED ME TO RETHINK THE HIGHLIGHTS I PLANNED ON EARLIER IN THE EVENING. DECIDED TO GO WITH A WINTER STORM WARNING ACROSS OUR EASTERN ZONES WHERE WE SHOULD GET A NICE SWATH OF 4 TO 7 INCHES OF SNOWFALL. THE STRONGER WINDS GET GOING THIS EVENING JUST AS THE SNOWFALL INTENSIFIES. THE BEST FRONTOGENESIS OCCURS BETWEEN 00Z AND 09Z AND NORTHWEST WINDS ACROSS THE WINTER STORM WARNING AREA SHOULD BE IN THE 20 TO 30 KNOT RANGE WITH HIGHER GUSTS. MODEL SOUNDING DATA ALSO AGREES WITH THIS ASSESSMENT. ALTHOUGH SNOW TOTALS WON'T REACH 6 INCH MARK ACROSS MOST OF THE AREA 4 TO 5 INCHES WILL BE COMMON. COMBINE THIS WITH THE EXPECTED HIGHER WIND SPEED AND THE FACT THAT THIS IS THE SEASONS FIRST BIG EVENT WARRANT A WINTER STORM WARNING. A WINTER WEATHER ADVISORY IS IN EVENT FOR VALLEY AND GARFIELD COUNTIES BUT MOSTLY ACROSS EASTERN PARTS OF THESE COUNTIES...WHERE 2 TO 3 INCHES WILL BE COMMON. SUNDAY NIGHT THROUGH MONDAY...THE MAIN TROUGH WILL BE CENTERED OVER MANITOBA AND THE EVENT SHOULD BE OVER WITH WITH ONLY A FEW ISOLATED SNOW SHOWERS POSSIBLE UP ACROSS THE NORTHEASTERN CWA. HIGH PRESSURE AND CLEARS SKIES SHOULD BE STARTING IN THE SOUTHWESTERN SECTIONS OF THE CWA AS WELL BUT AREAS WITH SNOW ON THE GROUND WILL SEE TEMPERATURES BELOW GUIDANCE FOR SURE. WE WILL PROBABLY SEE TEMPERATURES IN THE MID TO LOWER TEENS SUNDAY NIGHT AND MONDAY NIGHT. RSMITH .LONG TERM...MONDAY NIGHT THROUGH SATURDAY... LONG TERM BEGINS WITH DRY NORTHWEST FLOW...EVEN THROUGH A SHORTWAVE IS MOVING THROUGH THE FLOW IT SHOULD NOT HAVE ANY MOISTURE TO WORK WITH TO CREATE ANY PRECIPITATION ON TUESDAY. WEDNESDAY AND THURSDAY NO MAJOR SYSTEMS IN THE REGION AS ZONAL TO NORTHWEST FLOW TAKES OVER PER THE GFS/EC MODELS WHICH SEEMS REASONABLE. FRIDAY AND NEXT SATURDAY THE GFS AND EC ARE OUT OF PHASE WITH EACH OTHER THEREFORE WENT WITH SLIGHTLY ABOVE CLIMO ON POPS TO SLIP INTO THE FORECAST A SLIGHT CHANCE OF SNOW...HOWEVER CONFIDENCE IS EXTREMELY LOW AT THIS TIME. && .AVIATION... VFR TO BEGIN WITH THIS MORNING ACROSS THE AREA. THEN FROM SOUTHWEST AND SPREADING NORTHEAST MVFR TO IFR CONDITIONS WITH LOWERING CEILINGS AND VISIBILITY FROM SNOW STARTING AROUND 18Z. ALL AREAS CAN EXPECTED WIDESPREAD IFR CONDITIONS FROM 21Z THROUGH 09Z AND THEN SLOWLY IMPROVING CONDITIONS AFTER 09Z. PROTON && .GLASGOW WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY FROM NOON MDT TODAY TO 5 AM MST SUNDAY FOR CENTRAL AND SOUTHERN VALLEY...GARFIELD...NORTHERN VALLEY. WINTER STORM WARNING FROM 3 PM MDT THIS AFTERNOON TO 11 AM MST SUNDAY FOR DANIELS...SHERIDAN...WESTERN ROOSEVELT...MCCONE... RICHLAND...DAWSON...PRAIRIE...WIBAUX...EASTERN ROOSEVELT. && WEATHER.GOV/GLASGOW
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE GLASGOW MT 349 AM MDT SAT NOV 5 2011 MTZ018>020-023>027-062-061000- DANIELS-SHERIDAN-WESTERN ROOSEVELT-MCCONE-RICHLAND-DAWSON-PRAIRIE- WIBAUX-EASTERN ROOSEVELT- 349 AM MDT SAT NOV 5 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHEAST MONTANA. .DAY ONE...TODAY AND TONIGHT FIRST WINTER STORM OF THE SEASON TO AFFECT THE AREA STARTING THIS AFTERNOON LASTING INTO SUNDAY MORNING. SNOW MAY BEGIN AS A MIX OF RAIN AND SNOW EARLY THIS AFTERNOON BEFORE CHANGING OVER TO ALL SNOW BY MID AFTERNOON. SNOWFALL WILL BEGIN TO ACCUMULATE AT HIGHER ELEVATIONS THIS AFTERNOON AND AT LOWER ELEVATIONS BY LATE AFTERNOON. HEAVIEST SNOWFALL WILL OCCUR BETWEEN 3PM THIS AFTERNOON AND 3AM TONIGHT ACROSS THE REGION. SNOW WILL LINGER INTO SUNDAY MORNING OVER THE AREA. WINDS WILL INCREASE WITH THE PUSH OF COLD AIR THIS AFTERNOON AND WILL BLOW FROM THE NORTHWEST AT 15 TO 30 MPH WITH HIGHER GUSTS. THIS WILL CAUSE REDUCED VISIBILITY WITH THE FALLING SNOW. STORM TOTAL SNOWFALL ACROSS THE REGION WITH RANGE FROM 4 TO 5 INCHES SOUTH OF THE MISSOURI RIVER TO UP TO 7 INCHES ALONG THE CANADIAN BORDER. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. MTZ017-022-061-061000- CENTRAL AND SOUTHERN VALLEY-GARFIELD-NORTHERN VALLEY- 349 AM MDT SAT NOV 5 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHEAST MONTANA. .DAY ONE...TODAY AND TONIGHT A WINTER STORM WILL MOVE THROUGH EASTERN MONTANA AND WESTERN NORTH DAKOTA OVER THE NEXT 24 HOURS. ACROSS VALLEY AND GARFIELD COUNTIES THE WORST WINTER CONDITIONS WILL BE FROM LARSLAN TO FRAZER TO COHAGEN AND POINTS EAST WHERE 2 TO 3 INCHES OF SNOW WILL FALL FROM MID DAY TODAY THROUGH THE OVERNIGHT HOURS. FOR THE REMAINDER OF VALLEY AND GARFIELD COUNTIES LOOK FOR LESS THAN 2 INCHES OF SNOWFALL WHICH WOULD INCLUDE THE COMMUNITIES OF GLASGOW...OPHEIM AND JORDAN. NORTHWEST WINDS 15 TO 25 MPH WILL DEVELOP OVER THE REGION BY LATE THIS AFTERNOON AND LASTING INTO SUNDAY MORNING LOCALLY REDUCING THE VISIBILITY WHEN COMBINED WITH FALLING SNOW. LAKE WIND ADVISORY CONDITIONS WILL OCCUR ACROSS THE LAKE STARTING THIS AFTERNOON AND LASTING INTO SUNDAY. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. MTZ016-021-059-060-061000- CENTRAL AND SOUTHEAST PHILLIPS-PETROLEUM-NORTHERN PHILLIPS- SOUTHWEST PHILLIPS- 349 AM MDT SAT NOV 5 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHEAST MONTANA. .DAY ONE...TODAY AND TONIGHT MEASURABLE SNOWFALL IS EXPECTED AT SOME LOCATIONS ACROSS THE REGION THROUGH THE OVERNIGHT HOURS. SNOWFALL WILL BE LESS THAN ONE INCH TOTAL THROUGH SUNDAY. NORTHWEST WINDS BLOWING AT 10 TO 20 MPH WILL LOCALLY REDUCE VISIBILITIES WITH FALLING SNOW THIS AFTERNOON AND EVENING. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.
The national radar mosaic for the moment the first event began.
10 winter weather, 6 winter storm. Local standard time, as filed.
Cooperative and CoCoRaHS observers reported 2.5 to 3.2 inches of snowfall across the county. This was the first measurable snow storm of the season. The highest amount of 3.2 inches was reported at the Brockton 11.6N CoCoRaHS site.
Weather spotters and cooperative observers reported 1 to 2 inches of snowfall across the county. This was the first measurable snow storm of the season. The highest amounts of 2 inches were reported at the Grass Range 13NE and Winnett 12SW coop sites.
A cooperative observer and a public observer reported 2.5 to 3.5 inches of snowfall across the area. This was the first measurable snow storm of the season. The highest amount of 3.5 inches was reported at the Zortman coop site.
Cooperative observers reported 1 to 4 inches of snow fall across the county. This was the first measurable snow storm of the season. The highest amounts of 4 inches were reported at the Malta 7E and Malta 35S coop sites.
A cooperative observer reported 5 inches of snowfall at the Cohagen 22SE coop site. This was the first measurable snow storm of the season.
Cooperative observers reported 4 to 6 inches of snow across the county. This was the first measurable snow storm of the season. The highest amount of 6 inches was reported at the Circle 20N coop site.
Cooperative observers reported around 3 to 5.5 inches of snow across the county. This was the first measurable snow storm of the season. The highest amount of 5.5 inches was reported at the Opheim 12SE coop site.
Public and cooperative observers reported 2 to 6 inches of snow fall across the county. This was the first measurable snow storm of the season. The highest amount of 6 inches was reported at the Hinsdale 4SW coop site which is at the top of a higher plateau in the county.
A cooperative observer reported 2 inches of snowfall at the Port of Morgan border station coop site. This was the first measurable snow storm of the season.
Weather spotters, cooperative observers and CoCoRaHS observers reported 1.5 to 6 inches of snow across the county. This was the first measurable snow storm of the season. The highest amount of 6 inches was reported at the Wolf Point coop site.
Cooperative observers reported 2 to 5 inches of snow across the county. This was the first measurable snow storm of the season. The highest amount of 5 inches was reported at the Bloomfield 5NNE coop site.
A cooperative observer reported one inch of snow at Terry. This was the first measurable snow storm of the season.
Weather spotters, cooperative observers and CoCoRaHS observers reported 2 to 5 inches of snow across the county. This was the first measurable snow storm of the season. The highest amounts of 5 inches were reported along the higher elevations of the Big Sheep Divide.
Weather spotters, cooperative observers and CoCoRaHS observers reported 2 to 4 inches of snow across the county. This was the first snow storm of the season. The highest amount of 4 inches was reported at the Scobey 4NW coop site.
Weather spotters, cooperative observers and CoCoRaHS observers reported a range of from just a trace up to 5 inches of snow across the county. This was the first snow storm of the season. The highest amount of 5 inches was reported at the Outlook 5.6 WNW CoCoRaHS site.
Cooperative observers reported one half to 2.5 inches of snow across the county. This was the first measurable snow storm of the season. The highest amount of 2.5 inches was reported at the Carlyle coop 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: 354953, 354952, 354957, 354949, 354950, 354940, 354945, 354954, 354951, 354937, 354944, 354947, 354938, 354927, 354936, 354946.