Heavy Snow in Idaho, February 27 to 28, 2011

Name: Heavy Snow in Idaho, February 27 to 28, 2011
Start: 2011-02-27T02:00
End: 2011-02-28T23:59
Location: Idaho

February 27 to 28, 2011 · NWS OTX · 4 events in 4 counties and zones

Where it happened

Every event with a place to put it; 4 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.

Tornadoes
Tropical storms and surge
Floods
Wind
Hail
Winter weather
Heat and drought
Cold
Fire, smoke and dust
Marine and coastal
Other

Open the live radar over this ground

The toll

Deaths: 1
Injuries: 0
Property damage: None recorded
Crop damage: None recorded
Events: 4

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.

What happened

The episode as NWS OTX wrote it up.

An upper-level trough sagged down the British Columbia coastline and eventually into the Pacific Northwest. Ahead of the trough, moderate to strong west to southwest flow in the lower levels focused strong orographic flow into the Idaho Panhandle resulting in twenty four to sixty hours of heavy snow. During the two day period, the highest snowfall accumulations were generally above two thousand feet where reports ranged between one and two feet. Lower elevations generally experienced four to eight inches. Silver Mountain Ski Resort was forced to close on the 27th due to high winds and white out conditions. Heavy snow continued into March 1st for the Central Panhandle Mountains, Idaho Palouse, and Camas Prairie.

What forecasters said that day

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 Spokane, WA wrote its last area forecast discussion before the first event at Feb 26, 10:11 PM PST, 3 hours 49 minutes earlier.

Area forecast discussion, Feb 26, 10:11 PM PST, 3 hours 49 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
1011 PM PST SAT FEB 26 2011

.SYNOPSIS...HIGH PRESSURE WILL BREAK DOWN THIS EVENING IN RESPONSE
TO ANOTHER COLD STORM SYSTEM THAT IS EXPECTED TO ARRIVE LATE
TONIGHT INTO SUNDAY. EXPECT HEAVY ACCUMULATING SNOWS IN THE
CASCADES...FAR EASTERN WASHINGTON AND THE IDAHO PANHANDLE VALLEYS
LATE SUNDAY INTO MONDAY. AN ACTIVE AND UNSETTLED WEATHER PATTERN
WILL LIKELY CONTINUE INTO MUCH OF NEXT WEEK.

&&

.DISCUSSION...

UPDATE...A RATHER COMPLEX EVOLUTION INVOLVING TWO SEMI-DISTINCT
FEATURES ROLLING THROUGH THE AREA OVER THE NEXT 48 HOURS COMBINED
WITH WIND POTENTIAL AND BLOWING SNOW PROBLEMS HAS YIELDED A
PLETHORA OF WINTER HEADLINES ACROSS THE AREA FOR THE NEXT COUPLE
OF DAYS. IMPACTS FROM THE SERIES OF STORMS WILL VARY WILDLY FROM
PLACE TO PLACE...WITH THE MOST SIGNIFICANT IMPACTS LIKELY IN THE
CASCADES...MOUNTAINS OF NORTHEAST WASHINGTON...AND THE MOUNTAINS
OF THE IDAHO PANHANDLE. VALLEY LOCATIONS IN NORTHEAST WASHINGTON
AS WELL AS THE NORTHERN IDAHO PANHANDLE ARE ALSO LIKELY TO SEE
SIGNIFICANT IMPACTS TO TRAVEL DUE TO HEAVY SNOW ACCUMULATIONS.
MODERATE IMPACTS FROM SNOWFALL AND BLOWING SNOW ARE LIKELY AROUND
SPOKANE...HOWEVER BECAUSE THE HEAVIEST SNOWFALL IS LIKELY TO FALL
DURING THE DAYTIME SUNDAY AND AGAIN DURING THE DAYTIME ON
MONDAY...ROAD CONDITIONS ARE UNLIKELY TO DETERIORATE AS QUICKLY IN
THE SPOKANE AREA DUE TO THE HIGH LATE WINTER SUN ANGLE. FOR THE
PALOUSE...SNOWFALL WILL INCREASE ON SUNDAY AND INTENSIFY
MONDAY...HOWEVER TIMING AND MARGINAL TEMPERATURES MAKE THE IMPACTS
FAIRLY UNCERTAIN. IT SEEMS LIKELY...HOWEVER...THAT ACCUMULATIONS
WILL OCCUR AND BE AT LEAST MODERATE OFF OF THE MORE HEAVILY
TRAVELED ROADS. ADVISORIES OR WARNINGS WILL LIKELY NEED TO BE
CONSIDERED BY THE MIDNIGHT SHIFT FOR THESE AREAS ONCE A BIT MORE
CLARITY IS GAINED INTO THE TEMPERATURES.

WATER VAPOR IMAGERY THIS EVENING ALREADY SHOWS A DEEPENING UPPER
LEVEL SYSTEM DROPPING DOWN THE NORTHERN COAST OF BRITISH COLUMBIA.
A NARROW NORTHWEST TO SOUTHEAST ORIENTED MOISTURE FETCH IS
POSITIONED IN ADVANCE OF THIS SYSTEM AND IS BEGINNING TO EDGE FROM
SOUTHERN BRITISH COLUMBIA INTO NORTHERN WASHINGTON. WEAK
ISENTROPIC ASCENT DUE TO WARM ADVECTION ALOFT IS ALREADY OCCURRING
ACROSS THE AREA...WITH GFS DEPICTIONS PLACING THE BULK OF THIS
BETWEEN 280 AND 290K. THIS IS ALSO SMACK IN THE DENDRITIC GROWTH
LAYER. HOWEVER...MOISTURE IN THE LAYER IS UNIMPRESSIVE...AS
EVIDENCED BY CONDENSATION PRESSURE DEFICITS GENERALLY IN THE 20-30
MB RANGE THIS EVENING AND A GENERAL LACK OF MUCH MORE THAN FLURRY
REPORTS THIS EVENING. HOWEVER...AS THE NIGHT PROGRESSES THESE
VALUES FALL OFF TO BELOW 10 MB GENERALLY EAST OF A REPUBLIC TO
PULLMAN LINE...SO ALL OF THESE AREAS ARE AT LEAST LIKELY TO SEE
SNOW DEVELOP OVERNIGHT. MORE EVIDENCE OF THE MOISTENING OF THE
COLUMN IS EVIDENCED BY MIXING RATIOS IN THE 280-290K LAYER SURGING
FROM AROUND 1 G/KG SATURDAY AFTERNOON TOWARD 2.5-3 G/KG DURING THE
DAY ON SUNDAY. THE COMBINATION OF ISENTROPIC ASCENT CO-LOCATED
WITH THE DENDRITIC ZONE...AN INCOMING RIGHT ENTRANCE REGION OF A
JET STREAK...LOW-LEVEL SOUTHWESTERLY UPSLOPE FLOW...AS WELL AS
RATHER STEEPENING LAPSE RATES THROUGH THE DAY SUNDAY MAKE HEAVY
SNOW ACCUMULATION A FAIRLY SURE BET EVERYWHERE NORTH AND EAST OF
SPOKANE. MODEL QPF BASICALLY MIRRORS THIS TREND WITH AROUND A
QUARTER OF AN INCH EVERY SIX HOURS THROUGH THE DAY SUNDAY. WITH
RATIOS STARTING OFF LIKELY NORTH OF 20:1 THEN TRENDING TOWARD 10:1
BY SUNDAY NIGHT...SNOW ACCUMULATIONS THROUGH SUNDAY SEEM LIKELY TO
BE AROUND A HALF OF A FOOT IN THE VALLEYS OF FAR NE WASHINGTON AND
NORTH IDAHO. WHILE ACCUMULATIONS WILL LIKELY BE LIGHTER TOWARD
SPOKANE...2 TO 3 INCHES STILL SEEM LIKELY ON SUNDAY.

WINDS SEEM LIKELY TO BE ANOTHER PROBLEM THROUGH THE DAY SUNDAY
INTO SUNDAY NIGHT. GOOD MODEL AGREEMENT ON 850 MB FLOW SURPASSING
50 KTS EXISTS BETWEEN THE GFS AND NAM. IN ADDITION...BUFKIT
SOUNDINGS FROM BOTH SPOKANE AND PULLMAN MIX OUT THE BOUNDARY
LAYER. WHILE COLD AIR WILL LIKELY RETREAT A FAIR AMOUNT ON
SUNDAY...THE MODELS ALWAYS TEND TO TRY TO ERODE IT TOO QUICKLY.
THUS...WINDS WERE HELD OFF BY 3-6 HOURS IN THE FORECAST FROM WHAT
STRAIGHT MODEL OUTPUT WOULD SUGGEST. HOWEVER...ONCE THEY START
BLOWING...A COMBINATION OF FALLING AND BLOWING SNOW DUE TO THE
DRYNESS OF THE SNOW CURRENTLY ON THE GROUND SEEMS LIKELY TO CAUSE
PROBLEMS ON THE PALOUSE...WEST PLAINS...AND IN MOST OF THE AREA
MOUNTAINS.

TEMPERATURES THROUGH THE PERIOD ARE FAIRLY WELL AGREED UPON...WITH
ALL AREAS GENERALLY NORTH OF PULLMAN LIKELY TO REMAIN FREEZING OR
LOWER UNTIL AT LEAST MONDAY. AS A RESULT...ALL SNOW IS EXPECTED IN
THESE AREAS...WITH AREAS FARTHER SOUTH AS WELL AS AROUND MOSES
LAKE AND WENATCHEE UNLIKELY TO SEE SIGNIFICANT PRECIPITATION...SO
P-TYPE IS MUCH LESS OF A FACTOR IN THESE OTHER LOCATIONS. /FRIES

&&

.AVIATION...
RADAR RETURNS AND SURFACE OBS INDICATE -SN IS CURRENTLY ENCOMPASSING
THE AREA FROM COLVILLE TO KCOE AND ALL POINTS NORTHEAST. AS THE
NIGHT PROGRESSES...THE ATMOSPHERE WILL MOISTEN PROGRESSIVELY FARTHER
WEST...WITH -SN LIKELY BY MORNING FROM KOMK TO KPUW AT NORTHEAST.
BETTER LIFT WILL TRAVERSE THROUGH KGEG...KSFF...AND KCOE SHORTLY
AFTER 12Z WITH A PERIOD OF MODERATE SN LIKELY FOR 2-6 HOURS.
SOUTHWEST FLOW OFF THE SURFACE WILL ALSO MIX DOWN GENERALLY AFTER
21Z AT KPUW...KGEG...AND EVEN KCOE WITH GUSTS UP TO 30 KTS LIKELY.
THIS WILL ALSO START BLOWING SNOW AT THESE SITES EVEN AS FALLING
SNOW LIGHTENS A BIT. /FRIES

&&

.PRELIMINARY POINT TEMPS/POPS...
SPOKANE         6  31  28  34  25  34 /  60 100  80  80  40  40
COEUR D'ALENE  11  31  28  34  24  35 /  70 100 100 100  40  40
PULLMAN        11  32  29  35  27  37 /  30  80  70 100  50  50
LEWISTON       16  38  32  42  30  43 /  10  20  20  60  60  60
COLVILLE       13  31  22  35  20  37 /  60 100  90  80  50  50
SANDPOINT      14  31  26  33  22  34 /  70 100 100  90  70  60
KELLOGG        12  31  27  33  23  35 /  70 100 100 100  80  60
MOSES LAKE     16  39  30  41  28  39 /  10  20  30  30  20  30
WENATCHEE      11  38  29  38  27  38 /  20  40  50  30  20  30
OMAK            7  33  24  36  22  37 /  20  70  70  50  20  30

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...WINTER STORM WARNING FROM 4 AM SUNDAY TO 4 PM PST MONDAY CENTRAL
     PANHANDLE MOUNTAINS...COEUR D'ALENE AREA...NORTHERN
     PANHANDLE.

WA...WINTER STORM WARNING FROM 4 AM SUNDAY TO 4 PM PST MONDAY
     NORTHEAST MOUNTAINS.

     WINTER STORM WARNING FROM 10 AM SUNDAY TO 10 AM PST MONDAY EAST
     SLOPES NORTHERN CASCADES.

     WINTER WEATHER ADVISORY FROM 4 AM SUNDAY TO 4 PM PST MONDAY
     SPOKANE AREA.

&&

Hazardous weather outlook, Feb 26, 4:26 PM PST, 9 hours 34 minutes before

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE SPOKANE WA
426 PM PST SAT FEB 26 2011

IDZ001-002-004-WAZ036-037-042-280030-
NORTHERN PANHANDLE-COEUR D'ALENE AREA-CENTRAL PANHANDLE MOUNTAINS-
SPOKANE AREA-NORTHEAST MOUNTAINS-EAST SLOPES NORTHERN CASCADES-
426 PM PST SAT FEB 26 2011

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTH IDAHO...
NORTH CENTRAL WASHINGTON AND NORTHEAST WASHINGTON.

.DAY ONE...REST OF TODAY AND TONIGHT

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

A WINTER STORM WARNING HAS BEEN ISSUED FOR SUNDAY AND MONDAY...AND
A WINTER STORM WATCH IS IN EFFECT FOR SPOKANE.

A PAIR OF SYSTEMS WILL IMPACT THE AREA SUNDAY THROUGH THE MIDDLE
OF NEXT WEEK. THE FIRST WILL ARRIVE LATE TONIGHT AND LAST INTO
MONDAY...FOLLOWED BY A SECOND SYSTEM TUESDAY AND WEDNESDAY. HEAVY
MOUNTAIN SNOW ACCUMULATIONS ARE EXPECTED WITH 1 TO 3 FEET POSSIBLE
FOR ALL PASSES OF THE NORTH IDAHO PANHANDLE AND CENTRAL PANHANDLE
MOUNTAINS BY THURSDAY OF NEXT WEEK. THE VALLEYS OF NORTHEAST
WASHINGTON AND NORTH IDAHO MAY ALSO RECEIVE HEAVY SNOW
ACCUMULATIONS. THE EAST SLOPES OF THE CASCADES WILL ALSO RECEIVE
SIGNIFICANT ACCUMULATIONS ESPECIALLY NEAR THE CASCADE CREST.

IDZ003-026-027-WAZ031>035-038-041-043-044-280030-
IDAHO PALOUSE-LEWISTON AREA-LEWIS AND SOUTHERN NEZ PERCE COUNTIES-
NORTHEAST BLUE MOUNTAINS-LOWER GARFIELD AND ASOTIN COUNTIES-
WASHINGTON PALOUSE-MOSES LAKE AREA-UPPER COLUMBIA BASIN-
OKANOGAN HIGHLANDS-WENATCHEE AREA-OKANOGAN VALLEY-
WATERVILLE PLATEAU-
426 PM PST SAT FEB 26 2011

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTH IDAHO...
NORTH CENTRAL IDAHO...CENTRAL WASHINGTON...EAST CENTRAL
WASHINGTON...NORTH CENTRAL WASHINGTON AND SOUTHEAST WASHINGTON.

.DAY ONE...REST OF TODAY AND TONIGHT

HAZARDOUS WEATHER IS NOT EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

A PAIR OF SYSTEMS WILL IMPACT THE AREA SUNDAY THROUGH THE MIDDLE
OF NEXT WEEK. THE FIRST WILL ARRIVE LATE TONIGHT AND LAST INTO
MONDAY...FOLLOWED BY A SECOND SYSTEM TUESDAY AND WEDNESDAY.
SIGNIFICANT SNOW ACCUMULATIONS WILL BE POSSIBLE ACROSS THE
PALOUSE...WITH A RAIN AND SNOW MIX FOR THE LEWISTON REGION. LIGHT
SNOW ACCUMULATIONS ARE LIKELY FROM WENATCHEE NORTH TO OMAK.

The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

4 heavy snow. Local standard time, as filed.

Heavy Snow, Northern Panhandle

When: February 27, 2:00 AM PST to February 28, 2:00 PM PST
Where: Northern Panhandle forecast zone
Reported by: Trained Spotter
Coordinates: 48.247, -116.588 (the zone’s center; the record gives no point)

Heavy Snow, Central Panhandle Mountains

When: February 27, 4:00 AM PST to February 28, 11:59 PM PST
Where: Central Panhandle Mountains forecast zone
Deaths: 0 direct, 1 indirect
Reported by: Mesonet
Coordinates: 47.265, -116.491 (the zone’s center; the record gives no point)

Numerous reports of traffic accidents were reported in the Silver Valley due to this storm, which carried over into March 1st. The Idaho State Police reported seven crashes and fourteen slide-offs. One fatality was reported near Mullan, ID, but the gender and age of the deceased person is unknown.

Heavy Snow, Idaho Palouse

When: February 28, 1:00 PM PST to 11:59 PM PST
Where: Idaho Palouse forecast zone
Reported by: Trained Spotter
Coordinates: 47.017, -116.685 (the zone’s center; the record gives no point)

Heavy Snow, Lewis and Southern Nez Perce

When: February 28, 4:00 PM PST to 11:59 PM PST
Where: Lewis and Southern Nez Perce forecast zone
Reported by: Trained Spotter
Coordinates: 46.282, -116.588 (the zone’s center; the record gives no point)

The people who died

As the offices recorded each death: direct deaths were caused by the weather itself, indirect ones by something it set in motion.

Event	Date	Age	Sex	Where	Kind
Heavy Snow, Central Panhandle Mountains	2011-02-27			Vehicle/Towed Trailer	Indirect

What these are

Heavy Snow: Snowfall reaching the local warning threshold without the other hazards of a winter storm.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in Idaho in 2011 Every state in 2011 This day in weather history Warnings in Idaho, February 2011

Sources

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: 280024, 280025, 280026, 280027.