With strong low pressure to the northeast and high pressure to the southwest, a tight pressure gradient set up across central Montana, which favored the development of strong and gusty surface winds across portions of central Montana.
Every event with a place to put it; 1 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.
With strong low pressure to the northeast and high pressure to the southwest, a tight pressure gradient set up across central Montana, which favored the development of strong and gusty surface winds across portions of central 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 Dec 2, 9:35 PM MST, 1 hour 16 minutes earlier.
AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE GLASGOW MT 935 PM MST SUN DEC 2 2012 .SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH TUESDAY... THE MAIN CHANGE TO THE SHORT TERM UPDATE WAS TO INCREASE POPS ACROSS THE CENTRAL AND EASTERN COUNTIES OF OUR CWA TO BETTER REFLECT CURRENT OBSERVATIONS. CURRENT THINKING IS THAT COLD AIR WILL LAG BEHIND THE PRECIPITATION AND SO PRECIPITATION TYPE WILL CONTINUE TO BE PREDOMINANTLY RAIN. RAIN WILL EXIT FROM WEST TO EAST BETWEEN 06-09Z. SKY CONDITIONS WILL ALSO BEGIN TO IMPROVE FROM WEST TO EAST THROUGH THE OVERNIGHT HOURS AS CLOUDINESS LIFTS OUT OF THE FORECAST AREA. THE HIGH WIND WARNING IN PLACE FOR SOUTHWEST PHILLIPS COUNTY HAS BEEN KEPT IN PLACE FOR NOW...ALTHOUGH OBSERVATIONS SHOW THAT THERE HAVE NOT BEEN MANY WIND GUSTS ABOVE 35KT. THE 00Z NAM ALSO HAS WINDS OF ONLY 50-55KT AT 850MB ACROSS THAT AREA THROUGH EARLY TOMORROW AND IT IS UNLIKELY THAT THESE WILL MIX DOWN. WILL TAKE ANOTHER LOOK AT THE REST OF THE 00Z GUIDANCE THIS EVENING BUT THE HIGH WIND WARNING WILL LIKELY NEED TO BE DROPPED LATER TONIGHT AS IT IS BECOMING INCREASINGLY MORE LIKELY THAT WIND GUSTS ARE GOING TO CONTINUE TO FALL SHY OF WARNING CRITERIA. MALIAWCO PREVIOUS SHORT TERM DISCUSSION...A LARGE UPPER LOW OF THE BRITISH COLUMBIA COASTLINE CONTINUES TO ROTATE AND SEND LARGE VOLUMES OF PACIFIC MOISTURE ACROSS THE GREAT BASIN AND THE NORTHERN ROCKIES. A SHORTWAVE HAS EJECTED OUT OF THE UPPER LOW/TROUGH AND IS CURRENTLY MOVING ACROSS THE NORTHERN ROCKIES. PACIFIC MOISTURE IS BEING SPREAD AHEAD OF THIS SHORTWAVE INTO CENTRAL MONTANA WHERE THE RAIN CURRENTLY FALLING. WE HAVE ALSO SEEN LIGHT RAIN ACROSS PARTS OF EASTERN MONTANA THIS AFTERNOON. AS THE SHORTWAVE PUSHES A COLD FRONT ACROSS THE STATE THE AREA OF PRECIPITATION IN CENTRAL MONTANA WILL SHIFT EAST ALONG WITH THE COLD FRONT. THE WINDS WILL PICK UP BEHIND THIS COLD FRONT LATE THIS EVENING INTO MONDAY AFTERNOON AND THE WINDS WILL BE PARTICULAR STRONG ACROSS SW PHILLIPS COUNTY...THE LITTLE ROCKIES AND STATE HIGHWAY 191. STRONG WINDS WILL BEGIN BEFORE MIDNIGHT AND REMAIN HIGH THOUGH MONDAY MORNING BEFORE STARTING TO DROP OFF MONDAY AFTERNOON. WIND SPEEDS OF 30 TO 40 MPH SUSTAINED WITH WIND GUSTS OVER 60 MPH WILL BE POSSIBLE. SO A HIGH WIND WARNING WILL CONTINUE FOR SOUTHWEST PHILLIPS THROUGH MONDAY EVENING. THE REST OF THE CWA WILL ALSO SEE GUSTY WINDS IN THE 20 TO 35 MPH RANGE WITH OCCASIONAL GUST UP TO 45 MPH. THE NAM WINDS ARE LIGHTER THEN THE GFS FOR THE REST OF THE CWA. SEE NO REASON TO EXPAND THE HIGH WINDS WARNING TO ANY OTHER ZONE OTHER THEN THE LITTLE ROCKIES. MONDAY MORNING THROUGH TUESDAY...CAA BEHIND THE COLD FRONT WILL BRING A NOTICEABLE DROP IN TEMPERATURES FOR THE HI LINE. HIGHS ON MONDAY WILL REMAIN IN THE LOWER TO MID 30S NORTH OF HWY 2. TEMPERATURES WILL START TO MODERATE SLIGHTLY ON TUESDAY AS WEAK UPPER LEVEL RIDGING BUILDS ACROSS CENTRAL MONTANA. RSMITH .LONG TERM...TUESDAY NIGHT THROUGH SUNDAY... THE GOING FORECAST IS IN GOOD SHAPE AS DESCRIBED BELOW. THE ONLY CHANGE MADE WAS TO TREND DOWN TEMPS FOR NEXT WEEKEND AS MODELS HAVE MOVED INTO BETTER AGREEMENT REGARDING ANOTHER REINFORCING SHOT OF COLD AIR DROPPING SOUTHWARD OUT OF CANADA. GILCHRIST PREVIOUS LONG TERM DISCUSSION...UPPER RIDGE WILL TO THE EAST TUESDAY NIGHT AND WEDNESDAY. UPPER TROUGH WILL MOVE ACROSS THE CANADIAN PRAIRIES AND MONTANA WEDNESDAY AND WEDNESDAY NIGHT WHICH WILL BRING A COLD FRONT THROUGH THE FORECAST AREA WEDNESDAY AFTERNOON AND EVENING. LIMITED MOISTURE WITH THIS SYSTEM BUT A FEW RAIN SHOWERS REMAINS POSSIBLE ON WEDNESDAY SWITCHING TO SNOW SHOWERS WEDNESDAY NIGHT AS TEMPERATURES FALL. WILL MENTION A SLIGHT CHANCE FOR NOW. NORTHWEST FLOW ALOFT WILL PREVAIL FROM THURSDAY INTO THE WEEKEND WITH COLDER AIR MASS IN PLACE. COULD SEE A SNOW SHOWER ON THURSDAY WITH A SHORTWAVE IN THE NORTHWEST FLOW ALOFT. CANADIAN HIGH PRESSURE WILL KEEP WEATHER DRY THURSDAY NIGHT AND FRIDAY. THE MODEL DIFFERENCES START APPEARING TOWARDS THE WEEKEND WITH ECMWF MAINTAINING NORTHWEST FLOW ALOFT WITH SHORTWAVES WHILE GFS WANTS TO DIG AN UPPER TROUGH OVER MONTANA. EITHER WAY...THERE IS SOME POTENTIAL FOR SNOW WITH THE GFS ADVERTISING A BETTER CHANCE THAN THE ECMWF. WILL MENTION EITHER A CHANCE OR SLIGHT CHANCE OF SNOW FOR NOW. FORRESTER && .AVIATION... VFR. A COLD FRONT WILL SWEEP THROUGH THIS EVENING BRINGING AN INCREASE IN WINDS OUT OF THE WEST. THESE WINDS WILL CONTINUE INTO MONDAY...AND INCREASE BY MIDDAY MAKING FOR A WINDY DAY. MAINLY HIGH CLOUDS WILL DOMINATE LATE TONIGHT INTO MONDAY BEHIND THE FRONT. GILCHRIST/PROTON KGGW ASOS CONTINUES TO HAVE COMMUNICATIONS PROBLEMS. THE PROBLEMS ARE EXPECTED TO BE REPAIRED ON MONDAY. && .GLASGOW WATCHES/WARNINGS/ADVISORIES... HIGH WIND WARNING UNTIL 11 PM MST MONDAY FOR SOUTHWEST PHILLIPS. && WEATHER.GOV/GLASGOW
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE GLASGOW MT 246 PM MST SUN DEC 2 2012 MTZ016>027-059-061-062-031200- CENTRAL AND SOUTHEAST PHILLIPS-CENTRAL AND SOUTHERN VALLEY- DANIELS-SHERIDAN-WESTERN ROOSEVELT-PETROLEUM-GARFIELD-MCCONE- RICHLAND-DAWSON-PRAIRIE-WIBAUX-NORTHERN PHILLIPS-NORTHERN VALLEY- EASTERN ROOSEVELT- 246 PM MST SUN DEC 2 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHEAST MONTANA. .DAY ONE...THIS AFTERNOON AND TONIGHT GUSTY WESTERLY WINDS WILL DEVELOP BEHIND A COLD FRONT THIS EVENING. WESTERLY WINDS BETWEEN 15 TO 25 MPH WITH OCCASIONAL GUSTS UP TO 35 MPH CAN BE EXPECTED TONIGHT BEHIND THE FRONT. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY WEST WILL INCREASE TO 20 TO 35 MPH BY MIDDAY MONDAY...WITH GUSTS APPROACHING 45 MPH AT TIMES INTO MONDAY EVENING. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. MTZ060-031200- SOUTHWEST PHILLIPS- 246 PM MST SUN DEC 2 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHEAST MONTANA. .DAY ONE...THIS AFTERNOON AND TONIGHT A COLD FRONT WILL INTRODUCE STRONG WESTERLY WINDS TO THE AREA BEGINNING THIS EVENING. EXPECTED GUSTS IN EXCESS OF 60 MPH WILL MAKE TRAVEL HAZARDOUS...ESPECIALLY FOR HIGH PROFILE VEHICLES ALONG HIGHWAY 191 SOUTH OF MALTA TOWARD THE MISSOURI RIVER. A HIGH WIND WARNING IS IN EFFECT FOR SOUTHWEST PHILLIPS COUNTY THROUGH MONDAY EVENING. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY THE STRONG WESTERLY WINDS WILL CONTINUE THROUGH MONDAY EVENING. .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.
1 high wind. Local standard time, as filed.
Sustained winds of 40 mph or greater began late in the night on the 2nd and continued through mid-day on the 3rd at the Malta South US-191 DOT site, with the highest wind gust of 67 mph measured at 5:00 MST.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Montana in 2012Every state in 2012This day in weather historyWarnings in Montana, December 2012
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: 424971.