Strong westerly flow aloft produced high winds across portions of North Central Montana. Wind gusts in excess of 60 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 flow aloft produced high winds across portions of North Central Montana. Wind gusts in excess of 60 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 Apr 20, 4:30 AM MST, 4 hours 3 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREAT FALLS MT 530 AM MDT FRI APR 20 2012 UPDATED AVIATION .DISCUSSION... TODAY THROUGH SUNDAY...SHORT WAVE ENERGY AND AN AREA OF ASSOCIATED PRECIPITATION IS MOVING ACROSS WESTERN MONTANA AT THIS TIME. PRECIPITATION SHOULD CROSS THE CONTINENTAL DIVIDE THIS MORNING AND SPREAD EAST DURING THE AFTERNOON. PRECIPITATION WILL BE GENERALLY LIGHT. SURFACE LOW PRESSURE WILL MOVE SOUTHEAST OUT OF ALBERTA THIS MORNING RESULTING IN A TIGHTENING GRADIENT. STRONG WINDS WILL LIKELY DEVELOP ALONG THE ROCKY MOUNTAIN FRONT AND EASTERN GLACIER COUNTY. THE HIGH WIND WATCH HAS BEEN UPGRADED TO A HIGH WIND WARNING. BUFKIT ANALYSIS INDICATES THE STRONGEST WINDS WILL NOT QUITE MIX TO THE SURFACE BUT THE DATA DOES INDICATE AN AREA OF 40 TO 45 MPH WIND NEAR THE SURFACE. THIS WOULD SUGGEST THE GREATEST THREAT MAY COME FROM SUSTAINED WINDS RATHER THAN GUSTS. HOWEVER...HRRR ANALYSIS DOES INDICATE 50+ KNOT GUSTS DURING THE AFTERNOON ALONG THE ROCKY MOUNTAIN FRONT. WINDS AND PRECIPITATION DECREASE TONIGHT AS 500 MB HEIGHTS RISE AND THE FLOW ALOFT BECOMES MORE ANTICYCLONIC. DRY AND WARMER CONDITIONS WILL BE THE RULE SATURDAY AND SUNDAY AS THE UPPER RIDGE BUILDS OVER THE AREA. SOME MOISTURE AND INSTABILITY MOVE THROUGH THE RIDGE SATURDAY AFTERNOON AND AGAIN ON SUNDAY AND BRING THE POSSIBILITY OF AN ISOLATED SHOWER AND/OR THUNDERSTORM TO THE MOUNTAINS. CAPE PROFILES ARE NOT VERY IMPRESSIVE. TEMPERATURES WILL WARM EACH DAY AND WILL RUN SOME 10 TO 15 DEGREES ABOVE SEASONAL AVERAGES. EMANUEL SUNDAY NIGHT THROUGH FRIDAY...A DOMINANT UPPER-LEVEL RIDGE WILL KEEP VERY WARM TEMPERATURES AND NEAR RECORD HIGHS OVER THE FORECAST AREA ON MONDAY. BY TUESDAY...MODELS HINT AT THE RIDGE BEGINNING TO WEAKEN WITH SOUTHWEST FLOW ALOFT BECOMING THE DOMINANT FEATURE THOUGH WARM TEMPERATURES WILL PERSIST THROUGH WEDNESDAY. INCREASING MOISTURE AND INSTABILITY MAY GIVE WAY TO AFTERNOON THUNDERSTORMS...PARTICULARLY OVER THE HIGHER TERRAIN. A COOLING TREND IS PROJECTED DURING THE LATTER HALF OF THE FORECAST PERIOD THOUGH MODELS DIFFER ON HOW QUICKLY THE COOLER AIRMASS WILL ARRIVE AND THE TIMING. A SHORTWAVE TROUGH IS PROJECTED TO MOVE INTO THE NORTHERN ROCKIES WEDNESDAY NIGHT WITH THE BEST CHANCE FOR PRECIPITATION EXPECTED DURING THIS TIME. THERE IS STILL A FAIR AMOUNT OF UNCERTAINTY AS SOME MODELS KEEP THE RIDGE OVER THE AREA AND SLOW THE PROGRESSION OF NEXT STORM SYSTEM. MLV && .AVIATION... UPDATED 1200Z. SOUTHWESTERLY WINDS WILL INCREASE THIS MORNING AND TURN WESTERLY BY 15Z. IN ADDITION...INCREASING MOISTURE WILL BRING SHOWERS ALONG THE CONTINENTAL DIVIDE AND PARTS OF SOUTHWEST MONTANA. LIGHT SHOWERS MAY LOWER CEILINGS TO MVFR CATEGORY FOR A BRIEF TIME AND WIDESPREAD MOUNTAIN OBSCURATION IS EXPECTED. THE MAIN IMPACT WILL BE STRONG GUSTY WINDS ALONG THE CONTINENTAL DIVIDE AND ADJACENT PLAINS WHERE SUSTAINED WINDS OVER 35KTS AND GUSTS UP TO 50KTS ARE POSSIBLE AT KCTB. ELSEWHERE...WIND GUSTS UP TO 40KTS ARE POSSIBLE. WINDS WILL SUBSIDE AFTER 00Z. MLV && .PRELIMINARY POINT TEMPS/POPS... GTF 65 43 67 41 / 30 10 10 0 CTB 62 32 65 34 / 30 10 10 0 HLN 65 41 71 40 / 30 10 10 0 BZN 67 39 72 37 / 30 10 10 0 WEY 55 28 63 30 / 20 10 10 10 DLN 64 38 73 37 / 30 10 10 0 HVR 67 35 68 37 / 30 10 10 0 LWT 63 38 64 36 / 30 10 10 0 && .TFX WATCHES/WARNINGS/ADVISORIES... HIGH WIND WARNING UNTIL 9 PM MDT THIS EVENING EASTERN GLACIER... NORTHERN ROCKY MOUNTAIN FRONT...SOUTHERN ROCKY MOUNTAIN FRONT. && WEATHER.GOV/GREATFALLS
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE GREAT FALLS MT 530 AM MDT FRI APR 20 2012 MTZ009-010-048-211130- NORTHERN ROCKY MOUNTAIN FRONT-EASTERN GLACIER- SOUTHERN ROCKY MOUNTAIN FRONT- 530 AM MDT FRI APR 20 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTH CENTRAL MONTANA. .DAY ONE...TODAY AND TONIGHT A HIGH WIND WARNING IS IN EFFECT UNTIL 9 PM MDT TONIGHT. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS REQUESTED FOR REPORTS OF STRONG WINDS OR WIND DAMAGE. MTZ008-011>015-044>047-049>055-211130- BEAVERHEAD-HILL-CASCADE-CHOUTEAU- CENTRAL AND SOUTHERN LEWIS AND CLARK-MADISON-TOOLE-LIBERTY- EASTERN PONDERA-BLAINE-EASTERN TETON-JUDITH BASIN-FERGUS- JEFFERSON-BROADWATER-MEAGHER-GALLATIN- 530 AM MDT FRI APR 20 2012 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.
6 high wind. Local standard time, as filed.
Winds gust to 64 mph at East Glacier Park 1ENE (Two Medicine DOT site).
Winds gusted to 60 mph at the Cut Bank ASOS.
Winds gusted to 63 mph at Bynum 13W (Dellwo MSCN site).
Sustained winds of 42 mph were reported for several hours at Inverness 2E (Inverness DOT site).
Winds gusted to 58 mph at Fort Belknap 13S (Fort Belknap RAWS site).
Winds gusted to 58 mph at Geyser 7E.
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, April 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: 376468, 376469, 376472, 376470, 376471, 376474.