A strong upper level trough and cold front moved through North Central Idaho on April 19 through April 20. This storm produced heavy snow accumulations and gusty winds across these areas.
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 MSO wrote it up.
A strong upper level trough and cold front moved through North Central Idaho on April 19 through April 20. This storm produced heavy snow accumulations and gusty winds across these areas.
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 19, 5:25 PM MST, 5 minutes earlier.
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
625 PM MDT SAT APR 19 2008
.UPDATE...PHONE CALLS TO WEATHER SPOTTERS ACROSS THE AREA INDICATE
THAT THE SNOW IS NOW BEGINNING TO STICK IN MOST VALLEY LOCATIONS
(EXCLUDING KALISPELL...BUTTE AND MISSOULA.) ACCUMULATIONS RIGHT NOW
ARE GENERALLY IN THE ONE TO THREE INCH RANGE.
&&
.DISCUSSION...FOR THE REMAINDER OF TONIGHT A SECONDARY PUSH OF
MODIFIED ARCTIC AIR IS EXPECTED TO MOVE WEST FROM MARIAS PASS TO
COLUMBIA FALLS TO KALISPELL LATER THIS EVENING. THIS SHOULD
PRODUCE ANOTHER BURST OF SNOW AND BLOWING SNOW (FROM GUSTY WINDS.)
ELSEWHERE...MODERATE TO HEAVY SNOW ACCUMULATIONS ARE STILL
EXPECTED AS A MID LEVEL LOW PRESSURE AREA MOVES SOUTHEAST ACROSS
NORTH CENTRAL IDAHO AND SW MT OVERNIGHT. LATEST MODEL RUNS APPEAR
TO NOW HAVE THE LOW TRACKING A LITTLE FURTHER SOUTH THAN THE
PREVIOUS RUN AND ARE ALSO GENERATING A LITTLE LESS PRECIP. WITH
THAT SAID...CONFIDENCE IS LOW IN THE LATEST SOLUTIONS SINCE THEY
DID NOT INITIALIZE WELL. THEREFORE...THE PREVIOUS FORECAST MODEL
DATA IS PREFERRED.
&&
.AVIATION...A LARGE UPPER LEVEL TROUGH WILL SIT OVER THE
INTERMOUNTAIN WEST THROUGH EARLY NEXT WEEK. SNOW SHOWERS WILL
DECREASE VISIBILITY AND LOWER CEILINGS AT TIMES THIS AFTERNOON AND
TONIGHT. ALONG WITH THESE SHOWERS WINDS WILL GET RATHER GUSTY AT
TIMES.
&&
.PREV DISCUSSION... /ISSUED 235 PM MDT SAT APR 19 2008/
DISCUSSION...ARCTIC AIRMASS STILL SEEPING INTO NORTHWEST MONTANA
THIS AFTERNOON AND CAN BE SEEN DISTINCTIVELY IN THE TEMPERATURES
THIS HOUR. GETTING SOME OVER RUNNING SNOW OVER NORTHWEST MONTANA
AS MOISTURE WRAPPING AROUND UPPER LOW OVER WASHINGTON. MODELS ARE
INDICATING THAT EXTREME NORTHWEST MONTANA AND THE NORTHERN
CLEARWATERS WILL MISS OUT ON THIS SYSTEM AS DRIER AIR WRAPS OVER
THIS REGION. THEREFORE WIDESPREAD ACCUMULATING SNOW IS NO LONGER
EXPECTED AND HAVE CANCELLED THE ADVISORIES. THE REMAINDER OF THE
WINTER HIGHLIGHTS LOOK ON TRACK ALTHOUGH THINK THE FLATHEAD AND
MISSION VALLEY WILL REALLY GET GOING AROUND SUNSET AND THE
MISSOULA BITTERROOT VALLEY AFTER MIDNIGHT AS MORE ARCTIC AIR MOVES
IN AND THE UPPER LOW NUDGES CLOSER TO THE INTER MOUNTAIN WEST. THOSE
STARTING TIMES HAVE BEEN ADJUSTED ACCORDINGLY. ALONG THE DIVIDE
AND SOUTHWEST MONTANA THROUGH LEMHI COUNTY IS STILL EXPECTED TO
SEE WIDESPREAD SNOW AND BLOWING SNOW ANTICIPATED ACROSS THE
SOUTHWEST AS THE INCREASED PRESSURE GRADIENT AND SHOWERS WILL HELP
MIX HIGH LEVEL WINDS TO THE SURFACE FOR PLENTY OF VISIBILITY
ISSUES FROM BLOWING AND DRIFTING SNOW. CURRENT HEADLINES HANDLE
THIS WELL. SUNDAY THE UPPER LOW WILL CONTINUE TO SPIN OVER THE
PACIFIC NORTHWEST AND THE ATMOSPHERE WILL REMAIN UNSTABLE. THE
HEAVIEST SNOW IS ANTICIPATED IN THE MORNING WITH DECENT SHOWERS IN
THE AFTERNOON ADDING ADDITIONAL ACCUMULATIONS...ESPECIALLY TO THE
MOUNTAINS. THE SURFACE AND MID LEVEL FLOW LOOKS VERY FAVORABLE FOR
ACCUMULATING SNOW OVER THE CAMAS PRAIRIE INCLUDING GRANGEVILLE AND
COTTONWOOD. THEREFORE ISSUED A SNOW ADVISORY FOR SUNDAY. SOME
LOCAL BLOWING SNOW IS ALSO POSSIBLE OVER THE WHITE BIRD GRADE.
MONDAY THROUGH THURSDAY...THE UNSTABLE AIRMASS CONTINUES ON MONDAY
KEEPING CHANCES OF SNOW GOING THROUGH THE DAY. MODELS IN FAIRLY GOOD
AGREEMENT THROUGH THURSDAY WITH THE LARGE SCALE FEATURES. DEEP UPPER
LEVEL TROUGH CONTINUES TO ROTATE AROUND THE NORTHWEST BRINGING
INTERMITTENT WAVES THROUGH THE FLOW. A SOUTHERLY WIND WILL PUSH A
WARM FRONT THROUGH ON TUESDAY THAT SHOULD BRING A LITTLE WARM
UP...BUT HIGHS WILL STILL HOLD BELOW AVERAGE. MODELS DIVERGE AFTER
THURSDAY AS THE GFS BUILDS A RIDGE INTO THE NORTHWEST WHILE EUROPEAN
KEEPS THE TROUGH IN PLACE SO KEPT PERSISTENCE IN THE FORECAST GOING
INTO LATE NEXT WEEK.
AVIATION...A LARGE UPPER LEVEL TROUGH WILL SIT OVER THE
INTERMOUNTAIN WEST THROUGH EARLY NEXT WEEK. SNOW SHOWERS WILL
DECREASE VISIBILITY AND LOWER CEILINGS AT TIMES THIS AFTERNOON AND
TONIGHT. ALONG WITH THESE SHOWERS WINDS WILL GET RATHER GUSTY AT
TIMES.
&&
.MSO WATCHES/WARNINGS/ADVISORIES...
MT... SNOW AND BLOWING SNOW ADVISORY UNTIL 12 PM MDT SUNDAY FOR
FLATHEAD/MISSION VALLEYS.
SNOW AND BLOWING SNOW ADVISORY UNTIL 12 PM MDT SUNDAY FOR WEST
GLACIER REGION.
WINTER STORM WARNING UNTIL 6 PM MDT SUNDAY FOR
BITTERROOT/SAPPHIRE MOUNTAINS.
HEAVY SNOW WARNING UNTIL 6 PM MDT SUNDAY FOR POTOMAC/SEELEY
LAKE REGION.
WINTER STORM WARNING UNTIL 6 PM MDT SUNDAY FOR BUTTE/BLACKFOOT
REGION.
SNOW ADVISORY FROM MIDNIGHT TONIGHT TO 12 PM MDT SUNDAY FOR
MISSOULA/BITTERROOT VALLEYS.
ID...SNOW ADVISORY FROM 5 AM TO 5 PM PDT SUNDAY FOR
OROFINO/GRANGEVILLE REGION.
HEAVY SNOW WARNING UNTIL 5 PM PDT SUNDAY FOR SOUTHERN
CLEARWATER MOUNTAINS.
SNOW ADVISORY FROM MIDNIGHT TONIGHT TO 6 PM MDT SUNDAY FOR
WESTERN LEMHI COUNTY.
WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 6 PM MDT SUNDAY
FOR EASTERN LEMHI COUNTY.
&&
UPDATE...HENRY
PREVIOUS DISCUSSION/AVIATION...MEAD/MLThe national radar mosaic for the moment the first event began.
1 heavy snow. Local standard time, as filed.
Idaho Department of Transportation snow plow crew reported 7.0 inches of storm total snow accumulation at Bannock Pass, ID. At Lemhi ridge, located 500 feet above the pass level, 10 inches of snow was reported by an automated snow reporting station.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Idaho in 2008Every state in 2008This day in weather historyWarnings in Idaho, April 2008
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: 87928.