A moist system moved into western Montana from the Pacific bringing some local heavy snowfall totals.
Every event with a place to put it; 5 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 MSO wrote it up.
A moist system moved into western Montana from the Pacific bringing some local heavy snowfall totals.
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 Missoula, MT wrote its last area forecast discussion before the first event at Apr 6, 2:42 AM MST, 7 hours 18 minutes earlier.
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
342 AM MDT FRI APR 6 2012
...HEAVY SNOW IN SOUTHWEST MONTANA AND EAST CENTRAL IDAHO THROUGH
FRIDAY NIGHT...
...LIGHT ACCUMULATING SNOW IN THE MISSOULA AND BITTERROOT VALLEYS...
...DIFFICULT COMMUTE IN SOUTHWEST MONTANA THIS MORNING...
.DISCUSSION...THE MORNING COMMUTE WILL BE DIFFICULT IN SOUTHWEST
MONTANA THIS MORNING...ESPECIALLY ALONG I-90 FROM DEERLODGE TO
HOMESTAKE PASS AND HIGHWAY 1 FROM DEERLODGE TO TO ANACONDA. TRAVEL
OVER LOST TRAIL...MCDONALD AND HOMESTAKE PASSES WILL BE VERY
DIFFICULT THIS MORNING AS SNOW INTENSIFIES THIS MORNING WHERE
PERHAPS UP TO A FOOT OF SNOW WILL FALL BY THIS EVENING.
SNOW HAS ALREADY STARTED IN SOUTHWEST MONTANA AND EAST CENTRAL
IDAHO UNDER A DEVELOPING AND INTENSIFYING WEATHER DISTURBANCE
MOVING NORTH FROM EAST CENTRAL IDAHO. THIS SYSTEM WILL GAIN
FURTHER STRENGTH BY SUNRISE AND PRODUCE THE HEAVIEST SNOWFALL
EARLY THIS MORNING THROUGH THE MID AFTERNOON HOURS. SNOWFALL RATES
OF AN INCH AN HOUR ARE POSSIBLE IN SOUTHWEST MONTANA THIS MORNING.
OTHER IMPACTS AS THIS STORM INTENSIFIES THIS MORNING:
LIGHT ACCUMULATING SNOWS IN THE BITTERROOT AND MISSOULA VALLEYS
WITH LOCALLY HIGHER AMOUNTS IN THE FOOTHILLS AND BENCHES.
ACCUMULATING SNOW IMPACTING TRAVEL ALONG HIGHWAY 83 AND HIGHWAY
200 IN WEST CENTRAL MONTANA.
THIS STORM WILL EXIT THE REGION BY SATURDAY MORNING AND ALLOW A
STRONG RIDGE TO DEVELOP OVER THE NORTHERN ROCKIES. MODELS AGREE ON
KEEPING THIS RIDGE IN PLACE THROUGH TUESDAY RESULTING IN DRY AND
MUCH WARMER CONDITIONS. TEMPERATURES MONDAY AND TUESDAY WILL BE
10-15 DEGREES ABOVE NORMAL. IT IS NOT OUT OF THE QUESTION MISSOULA
COULD SEE ITS FIRST 70 DEGREE DAY BY TUESDAY.
MID TO LATE NEXT WEEK THE WEATHER BECOMES MORE UNSETTLED. MODELS
PUSH THE RIDGE EAST OF THE AREA WHICH WILL RESULT SCATTERED
SHOWERS YET TEMPERATURES MORE NEAR NORMAL. THERE ARE A VARIETY OF
DIFFERENCES WITH MODEL SOLUTIONS SO CLIMATOLOGY WILL BE USED FOR
THIS PERIOD.
&&
.AVIATION...STRONG SPRING STORM WILL PRODUCE MAJOR IMPACTS IN
SOUTHWEST MONTANA TODAY. SNOW WILL OCCUR AND BECOME HEAVY AT TIMES
ESPECIALLY THIS MORNING. IN ADDITION...LOW VISIBILITIES AND
MOUNTAIN OBSCURATIONS WILL OCCUR AT KBTM. SNOWFALL RATES OF AN
INCH AN HOUR ARE POSSIBLE AT TIMES THIS MORNING AT KBTM. ELSEWHERE
KMSO AND KSMN WILL ALSO EXPERIENCE LOW CEILING AND MOUNTAIN
OBSCURATIONS DUE TO DEVELOPING SNOW THIS MORNING THROUGH THIS
AFTERNOON. ACCUMULATIONS WILL BE LESS IN THESE AREAS...GENERALLY
AN INCH OR TWO. KGPI WILL LIKELY RECEIVE LIGHT SNOW WITH LITTLE
ACCUMULATIONS EXPECTED. SHOWERS DEVELOPING LATER TONIGHT. THE
SHOWERS WILL LOWER VISIBILITIES AT THE AIRPORTS AND OBSCURE THE
MOUNTAINS AND PASSES. LOW CEILINGS AND VISIBILITIES WILL REMAIN
INTO FRIDAY.
&&
.MSO WATCHES/WARNINGS/ADVISORIES...
MT...WINTER STORM WARNING UNTIL 6 AM MDT SATURDAY BUTTE/BLACKFOOT
REGION.
WINTER WEATHER ADVISORY UNTIL 6 AM MDT SATURDAY
BITTERROOT/SAPPHIRE MOUNTAINS.
WINTER WEATHER ADVISORY UNTIL 6 AM MDT SATURDAY
MISSOULA/BITTERROOT VALLEYS...POTOMAC/SEELEY LAKE REGION.
WINTER WEATHER ADVISORY UNTIL 6 AM MDT SATURDAY WEST GLACIER
REGION.
ID...WINTER WEATHER ADVISORY UNTIL 6 AM MDT SATURDAY EASTERN
LEMHI COUNTY.
WINTER STORM WARNING UNTIL 6 AM MDT SATURDAY FOR LOST TRAIL PASS.
&&
SHORT TERM...RPN
LONG TERM....RPN
AVIATION...RPNPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MISSOULA MT
800 AM MDT FRI APR 06 2012
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0754 AM SNOW 7 NW ANACONDA 46.20N 113.04W
04/06/2012 M4.2 INCH DEER LODGE MT TRAINED SPOTTER
STILL SNOWING LIGHTLY
&&
PALLISTEPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MISSOULA MT
821 AM MDT FRI APR 06 2012
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0819 AM HEAVY SNOW 7 S BUTTE 45.90N 112.53W
04/06/2012 M6.0 INCH SILVER BOW MT TRAINED SPOTTER
STILL SNOWING LIGHTLY, SOME BLOWING AND DRIFTING
OVERNIGHT
&&
PALLISTEThe national radar mosaic for the moment the first event began.
5 heavy snow. Local standard time, as filed.
A snowfall total of 7 inches was measured in Butte.
A spotter measured 8 inches of snow 1 mile west-southwest of Georgetown.
A spotter measured 9 inches of snow 7 miles south of Butte.
A spotter estimated 6 inches of snow in Philipsburg.
A spotter measured 8.3 inches of snow in Anaconda.
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: 376109, 376111, 376113, 376114, 376112.