Strong winds developed over Madison County during the early to midmorning hours. Sustained wind speeds of 40 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 winds developed over Madison County during the early to midmorning hours. Sustained wind speeds of 40 mph were reported.
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 Dec 30, 10:10 AM MST, 20 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREAT FALLS MT 1010 AM MST FRI DEC 30 2011 .DISCUSSION... UPDATE FORTHCOMING. FORECAST IN GOOD SHAPE. HAVE LOWERED AFTERNOON HIGHS SOME LOCATIONS AND ADJUSTED THE SKY GRID. WILL CONTINUE THE WINTER WEATHER HIGHLIGHTS AS THE UPPER TROF CONTINUES TO APPROACH MONTANA FROM THE WEST. EMANUEL && .AVIATION... UPDATED 1148Z. WIDESPREAD MOUNTAIN OBSCUREMENT IN SNOW OVER THE ROCKY MOUNTAIN FRONT WILL SPREAD TO SOUTHWEST MONTANA THIS AFTERNOON AND CONTINUE AT LEAST THROUGH THE EVENING. THE PLAINS SHOULD SEE VFR CONDITIONS THROUGH TONIGHT. IN THE SOUTHWEST VALLEYS EXPECT VFR CONDITIONS THIS MORNING BUT THEN THERE WILL BE A THREAT OF MVFR CONDITIONS LATER THIS AFTERNOON INTO THIS EVENING. EXPECT AT LEAST A BRIEF PERIOD OF PRECIPITATION FOR THE KHLN AND KBZN TAFS. THE PROBLEM WILL BE WHEN THE PRECIPITATION FALLS. IF PRECIPITATION FALLS THIS AFTERNOON AND EARLY EVENING EXPECT RAIN WITH LIKELY VFR CONDITIONS. ON THE OTHER HAND IF PRECIPITATION HOLDS OFF UNTIL EVENING AND PARTICULARLY LATE EVENING EXPECT PRECIPITATION WILL BE SNOW WITH A BETTER CHANCE FOR MVFR CONDITIONS. THERE WILL EVEN BE A SMALL THREAT FOR IFR CONDITIONS BUT SHOULD IFR CONDITIONS DEVELOP DO NOT THINK THEY WOULD LAST MORE THAN AN HOUR. FEEL FAIRLY CONFIDENT WITH WINDS THROUGH THIS AFTERNOON AND ALSO THE TIMING OF THE COLD FRONTAL PASSAGE. HOWEVER BEHIND THE FRONT CONFIDENCE IS LOW WITH FORECAST WIND SPEEDS. BLANK && .PREV DISCUSSION...ISSUED 348 AM MST FRI DEC 30 2011 TODAY THROUGH SUNDAY...AN UPPER RIDGE OVER THE AREA EARLY TODAY WILL SHIFT EAST AS MOIST SOUTHWEST FLOW ALOFT INCREASES. AN UPPER TROUGH IS FORECAST TO MOVE THROUGH THE FORECAST AREA LATE TONIGHT AND EARLY SATURDAY MORNING. IT WILL BE PRECEDED BY A COLD FRONT WHICH WILL MOVE TO NEAR THE CONTINENTAL DIVIDE BY AROUND NOON TODAY THEN THROUGH THE REMAINDER OF THE FORECAST AREA THIS AFTERNOON AND EARLY EVENING. GOOD DOWNSLOPE FLOW SHOULD KEEP THE PLAINS MOSTLY DRY WITH THIS SYSTEM WHILE THE MOUNTAINS SHOULD RECEIVE SNOW. PRECIPITATION IS EXPECTED TO DIMINISH SATURDAY OVER THE MOUNTAINS IN THE WAKE OF THE UPPER TROUGH. AN UPPER RIDGE WILL GRADUALLY APPROACH THE AREA SATURDAY NIGHT AND SUNDAY. IN LINE WITH THIS EXPECT GENERALLY DRY CONDITIONS. AS FOR THE WINTER WEATHER HIGHLIGHTS ALREADY IN PLACE HAVE DROPPED THE LOWER ELEVATIONS OF SOUTHWEST MONTANA. IN THIS PARTICULAR AREA RELATIVELY WARM TEMPERATURES TODAY INTO THIS EVENING SHOULD RESULT IN PRECIPITATION FALLING MAINLY AS RAIN. THE NORRIS HILL AREA IS REACHING HIGH WIND CRITERIA SO WILL ISSUE A HIGH WIND WARNING FOR A PORTION OF MADISON COUNTY INTO THIS EARLY EVENING. IN THE AREA OF NORRIS HILL EXPECT WINDS TO DIMINISH BY LATE THIS EVENING BEHIND THE COLD FRONT. PLAN TO HOLD OFF ON HIGH WIND HIGHLIGHTS FOR THE REMAINDER OF THE AREA. A BAND OF STRONGER WINDS IS FORECAST TO DEVELOP OVER AT LEAST THE CENTRAL ZONES OVERNIGHT BUT DO NOT SEE A GOOD MECHANISM TO MIX THE WINDS DOWN TO THE SURFACE. THUS CONFIDENCE IS LOW FOR HIGH WINDS. BLANK SUNDAY NIGHT THROUGH FRIDAY...BREEZY CONDITIONS WILL REMAIN THROUGH MUCH OF THE EXTENDED. WITH HIGH PRESSURE DOMINATING THE EXTENDED FORECAST...WARMER TEMPERATURES AND DRIER CONDITIONS EAST OF THE ROCKIES SHOULD LEADED TO A MILDER QUIET PERIOD FOR MOST OF NEXT WEEK. THE UPPER LEVEL RIDGE WILL CONTINUE TO STRENGTHEN AND DEEPEN AS ITS AIS MOVES OVER THE ROCKY MOUNTAIN SPINE. SUNDAY NIGHT AND MONDAY. A WEEK SERIES OF EMBEDDED SHORTWAVES ARE FORECASTED TO MOVE THROUGH LATE MONDAY AND TUESDAY...BRIEFLY FLATTENING THE RIDGE AND MOVING THE JET STREAM BACK OVER THE FRONT RANGE OF THE ROCKIES. SOME SHOWERS COULD OCCUR AT HIGHER ELEVATIONS AND THERE IS A CHANCE OF SOME STRONGER WINDS AS WELL DURING THIS TIME PERIOD. BY THE MIDDLE OF THE WEEK THE RIDGE RESTRENGTHENS AHEAD OF THE NEXT TROUGH THAT WILL MOVE THROUGH THE AREA TOWARDS THE END OF THE EXTENDED PERIOD. MODEL SOLUTIONS ARE NOT IN VERY GOOD AGREEMENT ABOUT THE LOCATION AND STRENGTH OF THIS SYSTEM LATE IN THE FORECAST PERIOD. THE ECMWF CONTINUES TO KEEP THE LOW AS PART OF THE LARGE SCALE TROUGH...HOWEVER TH GFS SLOWS THE SYSTEM DOWN AND CUTS THE LOW OFF OVER THE EASTERN GREAT BASIN. THIS GFS SOLUTION COULD CREATE SIGNIFICANTLY MORE MOISTURE FOR SOUTHWEST MONTANA AS WRAP AROUND MOISTURE COULD QUICKLY CAUSE WINTER WEATHER IMPACTS....WHERE THE ECMWF SOLUTION CREATES AN INDUCED SHORTWAVE RIDGE BETWEEN THE LATE PERIOD SYSTEM AND ANOTHER SHORTWAVE OFF THE WASHINGTON COAST. HAVE LEANED TOWARDS THE ECMWF SOLUTION...WITH A SLIGHT TWEAK IN POPS FOR THIS END OF PERIOD SYSTEM OVER THE SOUTHWEST MOUNTAINS TO INDICATE THE POTENTIAL FOR THE GFS SOLUTION...CONFIDENCE IS NOT HIGH IN THIS SIGNIFICANT DEVIATION FROM THE CURRENT FLOW REGIME THOUGH. SUK && .PRELIMINARY POINT TEMPS/POPS... GTF 50 28 36 16 / 10 20 10 10 CTB 47 24 32 10 / 10 10 10 10 HLN 48 24 36 15 / 50 40 10 0 BZN 49 24 35 9 / 40 70 10 0 WEY 32 13 20 -11 / 90 90 50 10 DLN 47 22 32 10 / 40 70 10 0 HVR 52 30 40 11 / 10 10 10 10 LWT 49 28 36 11 / 10 30 10 10 && .TFX WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 11 AM MST SATURDAY FOR ELEVATIONS ABOVE 5000 FEET FOR NORTHERN ROCKY MOUNTAIN FRONT...SOUTHERN ROCKY MOUNTAIN FRONT. WINTER WEATHER ADVISORY UNTIL 11 AM MST SATURDAY FOR ELEVATIONS ABOVE 6000 FEET FOR BEAVERHEAD... GALLATIN...MADISON. HIGH WIND WARNING UNTIL 8 PM MST THIS EVENING FOR MADISON. && SHORT TERM...EMANUEL/BLANK LONG TERM...SUK AVIATION...BLANK WEATHER.GOV/GREATFALLS
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE GREAT FALLS MT 539 AM MST FRI DEC 30 2011 MTZ009-048-311245- NORTHERN ROCKY MOUNTAIN FRONT-SOUTHERN ROCKY MOUNTAIN FRONT- 539 AM MST FRI DEC 30 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTH CENTRAL MONTANA. .DAY ONE...TODAY AND TONIGHT A WINTER WEATHER ADVISORY CONTINUES IN EFFECT ABOVE 5000 FEET. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY THE WINTER WEATHER ADVISORY WILL CONTINUE IN EFFECT UNTIL 11 AM MST SATURDAY. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME. MTZ008-055-311245- BEAVERHEAD-GALLATIN- 539 AM MST FRI DEC 30 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHWEST MONTANA. .DAY ONE...TODAY AND TONIGHT A WINTER WEATHER ADVISORY CONTINUES IN EFFECT ABOVE 6000 FEET. THE WINTER WEATHER ADVISORY IS NO LONGER IN EFFECT BELOW 6000 FEET. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY THE WINTER WEATHER ADVISORY ABOVE 6000 FEET WILL CONTINUE IN EFFECT UNTIL 11 AM MST SATURDAY. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME. MTZ010>014-044>047-049>054-311245- EASTERN GLACIER-HILL-CASCADE-CHOUTEAU- CENTRAL AND SOUTHERN LEWIS AND CLARK-TOOLE-LIBERTY- EASTERN PONDERA-BLAINE-EASTERN TETON-JUDITH BASIN-FERGUS- JEFFERSON-BROADWATER-MEAGHER- 539 AM MST FRI DEC 30 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...SATURDAY THROUGH THURSDAY THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME. MTZ015-311245- MADISON- 539 AM MST FRI DEC 30 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHWEST MONTANA. .DAY ONE...TODAY AND TONIGHT A WINTER WEATHER ADVISORY CONTINUES IN EFFECT ABOVE 6000 FEET. THE WINTER WEATHER ADVISORY IS NO LONGER IN EFFECT BELOW 6000 FEET. A HIGH WIND WARNING IS IN EFFECT. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY THE WINTER WEATHER ADVISORY ABOVE 6000 FEET WILL CONTINUE IN EFFECT UNTIL 11 AM MST SATURDAY. THE HIGH WIND WARNING WILL CONTINUE IN EFFECT UNTIL 8 PM MST THIS EVENING. .SPOTTER INFORMATION STATEMENT... REPORTS OF HIGH WINDS OR WIND DAMAGE WOULD BE GREATLY APPRECIATED.
1 high wind. Local standard time, as filed.
Sustained wind speeds of 40 mph were reported for several hours at McAllister 4NNE (the Norris Hill 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, December 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: 355298.