A vigorous spring storm brought heavy snow to portions of the Rocky Mountain Front and adjacent plains. Snow amounts in excess of 6 inches 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.
A vigorous spring storm brought heavy snow to portions of the Rocky Mountain Front and adjacent plains. Snow amounts in excess of 6 inches 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 2, 4:40 AM MST, 20 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREAT FALLS MT 540 AM MDT SAT APR 2 2011 ...UPDATE TO AVIATION... .DISCUSSION... TODAY THROUGH MONDAY...MAIN WEATHER FOR THE WEEKEND CONTINUES TO BE THE UPPER TROF MOVING INTO MONTANA TODAY. THE FORECAST FOR THIS SYSTEM REMAINS A BIT OF A CHALLENGE GIVEN THE UNCERTAINTY ON HOW MUCH COLD AIR MOVES IN AND EXACTLY WHERE THE RAIN/SNOW LINE WILL FALL. TEMPERATURES WILL BE WARM AHEAD OF THE SYSTEM MEANING PRECIPITATION WILL BEGIN AS RAIN. AS THE COLD AIR BEGINS TO BE PULLED ACROSS THE AREA SATURDAY NIGHT...RAIN SHOULD TURN TO SNOW. STILL PRETTY CONFIDENT THE ROCKY MOUNTAIN FRONT WILL SEE SIGNIFICANT SNOW SO KEPT THE WARNING GOING THERE. HAVE DECIDED TO DROP THE WINTER STORM WATCH OVER THE REST OF THE CWA AS MODELS CONTINUE TO SUGGEST IT MAY BE TOO WARM FOR SIGNIFICANT SNOWFALL. MODELS DO INDICATE HEAVIEST PRECIPITATION WILL FALL SATURDAY NIGHT INTO EARLY SUNDAY MORNING WITH CONDITIONS SLOWLY IMPROVING SUNDAY AFTERNOON. WEAK RIDGING BETWEEN SYSTEMS LOOKS TO PASS THROUGH THE REGION ON MONDAY BREAKING OUT CLOUD COVER AND MAYBE EVEN BRINGING A LITTLE BIT OF SUN. TEMPERATURES WILL CONTINUE TO REMAIN COOL THROUGH THE PERIOD. MONDAY NIGHT THROUGH SATURDAY...MODEL SOLUTIONS FOR THE EXTENDED FORECAST PERIOD CONTINUE TO SHOW A SHORTWAVE RIDGE BEING FLATTENED MONDAY NIGHT AS AN UPPER LEVEL JET PUSHES INLAND. THIS FEATURE EVENTUALLY MOVES SOUTHEAST AND CARVES OUT AN UPPER LEVEL TROUGH OVER THE WESTERN CONUS BY WEDNESDAY NIGHT. MODELS ARE NOW IN A BIT BETTER AGREEMENT WITH THE STRENGTH AND LOCATION OF THIS TROUGH...WITH A CONSENSUS THAT THE CORE OF THE TROUGH WILL BE OVER THE GREAT BASIN ON THURSDAY. FLOW ALOFT BACKS TOWARD THE SOUTH AND PACIFIC MOISTURE INCREASES...ESPECIALLY ACROSS SOUTHWEST MONTANA. IT APPEARS THAT THE TROUGH WILL REMAIN OVER THE WESTERN CONUS THROUGH THE END OF THE WEEK BUT MODEL SOLUTIONS ONCE AGAIN DIVERGE WITH REGARD TO STRENGTH AND PLACEMENT OF THIS FEATURE. WILL CONTINUE TO GO WITH A FORECAST THAT KEEPS TEMPERATURES BELOW SEASONAL AVERAGES WITH POPS GENERALLY ABOVE CLIMATOLOGY. MPJ && .AVIATION... UPDATED 1140Z. AN UPPER LEVEL TROUGH WILL MOVE OVER THE INTERMOUNTAIN WEST TODAY AND OVER MONTANA TONIGHT. AT THE SURFACE A LOW PRESSURE SYSTEM OVER CENTRAL MONTANA WILL DEEPEN AND MOVE SOUTHEAST BY THIS EVENING. WIDESPREAD PRECIPITATION IS EXPECTED AS THIS SYSTEM WRAPS MOISTURE AROUND IT AND COMBINES WITH LOW LEVEL UPSLOPE FLOW EAST OF THE ROCKY MOUNTAINS. WIDESPREAD IFR CONDITIONS WILL DEVELOP OVER THE ROCKIES WITH MOUNTAINS OBSCURED AT TIMES. WIDESPREAD RAIN/SNOW AND IFR/MVFR CONDITIONS ARE EXPECTED OVER THE THE PLAINS TODAY WITH SNOW BECOMING MORE PREVALENT AFTER 03Z SUNDAY. MPJ && .PRELIMINARY POINT TEMPS/POPS... GTF 49 26 38 25 / 100 100 100 10 CTB 42 24 37 24 / 100 100 90 10 HLN 50 31 43 25 / 100 70 70 20 BZN 57 28 41 23 / 80 90 70 20 WEY 42 20 30 11 / 100 100 70 30 DLN 51 27 40 24 / 80 60 40 20 HVR 43 29 37 24 / 100 100 90 10 LWT 52 27 35 20 / 90 100 100 10 && .TFX WATCHES/WARNINGS/ADVISORIES... WINTER STORM WARNING UNTIL 6 PM MDT SUNDAY NORTHERN ROCKY MOUNTAIN FRONT...SOUTHERN ROCKY MOUNTAIN FRONT. && WEATHER.GOV/GREATFALLS
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE GREAT FALLS MT 328 AM MDT SAT APR 2 2011 MTZ009-048-030930- NORTHERN ROCKY MOUNTAIN FRONT-SOUTHERN ROCKY MOUNTAIN FRONT- 328 AM MDT SAT APR 2 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTH CENTRAL MONTANA. .DAY ONE...TODAY AND TONIGHT WINTER STORM WARNING REMAINS IN EFFECT FROM 6 AM SATURDAY TO 6 PM MDT SUNDAY. SNOW...HEAVY AT TIMES...IS EXPECTED OVER THE ROCKY MOUNTAIN FRONT FROM SATURDAY MORNING THROUGH THE DAY ON SUNDAY. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY WINTER STORM WARNING REMAINS IN EFFECT FROM UNTIL 6 PM MDT SUNDAY. .SPOTTER INFORMATION STATEMENT... REPORTS OF SNOWFALL OR SIGNIFICANT RESTRICTIONS TO VISIBILITY WOULD BE GREATLY APPRECIATED. MTZ008-010>015-044>047-049>055-030930- BEAVERHEAD-EASTERN GLACIER-HILL-CASCADE-CHOUTEAU- CENTRAL AND SOUTHERN LEWIS AND CLARK-MADISON-TOOLE-LIBERTY- EASTERN PONDERA-BLAINE-EASTERN TETON-JUDITH BASIN-FERGUS- JEFFERSON-BROADWATER-MEAGHER-GALLATIN- 328 AM MDT SAT APR 2 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL MONTANA...NORTH CENTRAL MONTANA AND SOUTHWEST MONTANA. .DAY ONE...TODAY AND TONIGHT SNOWFALL WILL BE SEEN ACROSS MOST OF MONTANA FROM SATURDAY THROUGH SUNDAY. WHILE CONDITIONS DO NOT CURRENTLY LOOK TO REACH WIDESPREAD WARNING CRITERIA...SOME LOCATIONS MAY SEE HEAVIER SNOWFALL. PLEASE MONITOR THE FORECAST FOR UPDATES. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW. .SPOTTER INFORMATION STATEMENT... REPORTS OF SNOWFALL OR SIGNIFICANT RESTRICTIONS TO VISIBILITY WOULD BE GREATLY APPRECIATED.
4 winter storm. Local standard time, as filed.
Eight inches of snow fell at Heart Butte 14SW (the Badger Pass SNOTEL site - elevation 6900 feet).
Six inches of snow fell at Rocky Boy 9SE (the Rocky Boy SNOTEL site - elevation 4700 feet).
Six inches of snow fell at Lloyd 5S.
Seven inches of snow fell at Dupuyer 15SW (the Dupuyer Creek SNOTEL site - elevation 5750 feet).
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, April 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: 292359, 292360, 292363, 292365.