After a strong cold front moved across Idaho on the 12th, abundent moisture moved into the region from the southwest, producing heavy snowfall at the pass levels.
Every event with a place to put it; 2 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.
After a strong cold front moved across Idaho on the 12th, abundent moisture moved into the region from the southwest, producing heavy snowfall at the pass levels.
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 Feb 15, 4:07 PM PST, 2 hours 53 minutes earlier.
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
507 PM MST TUE FEB 15 2011
.UPDATE...
WIND ADVISORY FOR GRANGEVILLE AND VICINITY ALLOWED TO EXPIRE.
&&
.DISCUSSION...
A SURFACE COLD FRONT HAS MOVED ACROSS THE CAMAS PRAIRIE LATE THIS
AFTERNOON...ALLOWING STRONG SOUTHERLY BREEZES TO DIMINISH IN THE
GRANGEVILLE AREA. THEREFORE...WIND HIGHLIGHTS ARE NO LONGER
NECESSARY AT THIS TIME.
&&
.AVIATION...GUSTY WINDS WILL CONTINUE AT MOST TERMINALS THROUGH
THE AFTERNOON. ESPECIALLY AS NEARBY SHOWERS BRING STRONGER WINDS
TO THE SURFACE. RAIN AND SNOW SHOWERS CONTINUE TO PROGRESS INTO
CENTRAL IDAHO AND NORTHWEST MONTANA. TERRAIN OBSCURATIONS WILL BE
POSSIBLE NEAR LOCATIONS OF HEAVIER PRECIPITATION. KGPI WILL
EXPERIENCE VISIBILITY AND CEILING REDUCTIONS DUE TO SNOWFALL. SOME
RAIN MAY MIX WITH SNOW AT TIMES THROUGH THE AFTERNOON ALLOWING
CONDITIONS TO IMPROVE AT TIMES. AFTER SUNSET SNOWFALL WILL START
TO REDUCE VISIBILITY AND THE CEILING AT KMSO.
&&
.PREV DISCUSSION... /ISSUED 242 PM MST TUE FEB 15 2011/
DISCUSSION...
TONIGHT THROUGH WEDNESDAY...A SOUTHWESTERLY FLOW ALOFT WILL
CONTINUE ACROSS THE NORTHERN ROCKIES REGION. A FRONTAL BOUNDARY
REMAINS DRAPED ACROSS NORTHEAST OREGON...THROUGH SOUTHEAST
WASHINGTON...AND INTO NORTHWEST MONTANA. COOL AIR NORTH OF THIS
BOUNDARY HAS ALLOWED SNOW LEVELS TO DIP ALL THE WAY TO THE VALLEY
FLOOR IN SOME AREAS...WHILE LOCATIONS SOUTH OF THE FRONT ARE MUCH
WARMER. LIGHT TO MODERATE PRECIPITATION ASSOCIATED WITH THIS
BOUNDARY WILL BE SAGGING SOUTH ACROSS THE WEST-CENTRAL MONTANA AND
NORTH-CENTRAL IDAHO LATER TONIGHT AND INTO WEDNESDAY. THIS SHIFT
IN THE FRONTAL POSITION WILL ALLOW SNOW LEVELS TO LOWER AS WELL AS
INTRODUCE STEADY PRECIPITATION TO IDAHO/CLEARWATER COUNTIES AND
PARTS OF WEST-CENTRAL MONTANA. FORECASTING SNOW LEVELS AND THE
CHANGE-OVER TO SNOW WILL BE A REAL CHALLENGE...AND IT ALL HINGES
ON THE MOVEMENT OF THE FRONT. AS THE UPPER LEVEL TROUGH APPROACHES
THE REGION FROM THE WEST ON WEDNESDAY...THE ATMOSPHERE WILL BECOME
INCREASINGLY MORE UNSTABLE AND COOLER. PRECIPITATION WILL BECOME
MORE SHOWERY IN NATURE. SEVERAL WINTER RELATED HIGHLIGHTS ARE IN
EFFECT.
STRONG WINDS HAVE RE-DEVELOPED IN THE GRANGEVILLE AREA THIS
AFTERNOON. THESE WINDS WILL BE DECREASING BY THIS EVENING AS THE
FRONTAL BOUNDARY APPROACHES FROM THE NORTH.
ON THURSDAY...A BROAD UPPER TROUGH WILL RESIDE OVER THE NORTHERN
ROCKIES REGION. THE ATMOSPHERE WILL BE COOLER AND REMAIN QUITE
UNSTABLE. EXPECT COOLER TEMPERATURES WITH PLENTY OF SNOW SHOWERS
DEVELOPING...ESPECIALLY DURING THE AFTERNOON.
ON FRIDAY A TROUGH OF LOW PRESSURE DIGGING ALONG THE PACIFIC COAST
WILL SLIGHTLY AMPLIFY A WEAK RIDGE OF HIGH PRESSURE OVER THE
NORTHERN ROCKIES WHILE PUSHING MOISTURE INTO THE REGION. THIS WILL
BRING THE CONTINUED POTENTIAL OF SHOWERS ALONG THE CANADIAN BORDER
AND OVER CENTRAL IDAHO. LONG RANGE MODEL SOLUTIONS DIVERGE OVER
THE WEEKEND AND INTO NEXT WEEK. THERE IS A LOT OF UNCERTAINTY IN
THE LONGER RANGE FORECAST SO MOST OF THE CHANCE OF PRECIPITATION
AND TEMPERATURES HAVE BEEN TRENDED TOWARDS CLIMATOLOGY. THERE WILL
LIKELY BE A TROUGH OF LOW PRESSURE DIGGING INTO THE REGION ON
SUNDAY OR MONDAY BUT THE TIMING AND PLACEMENT OF THIS FEATURE ARE
OFF BY A FULL DAY WHEN COMPARING THE GFS AND ECMWF MODELS.
AVIATION...GUSTY WINDS WILL CONTINUE AT MOST TERMINALS THROUGH
THE AFTERNOON. ESPECIALLY AS NEARBY SHOWERS BRING STRONGER WINDS
TO THE SURFACE. RAIN AND SNOW SHOWERS CONTINUE TO PROGRESS INTO
CENTRAL IDAHO AND NORTHWEST MONTANA. TERRAIN OBSCURATIONS WILL BE
POSSIBLE NEAR LOCATIONS OF HEAVIER PRECIPITATION. KGPI WILL
EXPERIENCE VISIBILITY AND CEILING REDUCTIONS DUE TO SNOWFALL. SOME
RAIN MAY MIX WITH SNOW AT TIMES THROUGH THE AFTERNOON ALLOWING
CONDITIONS TO IMPROVE AT TIMES. AFTER SUNSET SNOWFALL WILL START
TO REDUCE VISIBILITY AND THE CEILING AT KMSO.
&&
.MSO WATCHES/WARNINGS/ADVISORIES...
MT...WINTER WEATHER ADVISORY FROM 11 PM THIS EVENING TO 5 PM MST
WEDNESDAY MISSOULA/BITTERROOT VALLEYS.
WINTER WEATHER ADVISORY UNTIL 5 PM MST WEDNESDAY WEST GLACIER
REGION.
WINTER STORM WARNING UNTIL 5 PM MST WEDNESDAY ABOVE 4000 FEET
FOR THE BITTERROOT/SAPPHIRE MOUNTAINS.
WINTER WEATHER ADVISORY UNTIL 5 PM MST WEDNESDAY POTOMAC/SEELEY
LAKE REGION.
WINTER STORM WARNING UNTIL 5 PM MST WEDNESDAY ABOVE 4000 FEET
FOR THE LOWER CLARK FORK REGION.
ID...WINTER WEATHER ADVISORY FROM 10 PM THIS EVENING TO 7 PM PST
WEDNESDAY FOR WHITE BIRD GRADE.
WINTER STORM WARNING UNTIL 10 AM PST WEDNESDAY ABOVE 2000 FEET
FOR THE NORTHERN CLEARWATER MOUNTAINS.
WINTER WEATHER ADVISORY FROM 10 PM THIS EVENING TO 7 PM PST
WEDNESDAY OROFINO/GRANGEVILLE REGION.
WINTER STORM WARNING UNTIL 4 PM PST WEDNESDAY ABOVE 2500 FEET
FOR THE SOUTHERN CLEARWATER MOUNTAINS.
&&
UPDATE...ZUMPFE
SHORT TERM...MSJ
LONG TERM....LOEFFELBEIN
AVIATION...LOEFFELBEINThe national radar mosaic for the moment the first event began.
2 heavy snow. Local standard time, as filed.
A spotter in Grangeville measured 12 inches of snowfall in 24 hours.
Snowfall was measured at 11 inches by a coop observer 1 mile north of Dixie Idaho.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Idaho in 2011Every state in 2011This day in weather historyWarnings in Idaho, February 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: 280096, 280098.