Heavy Snow in Washington, March 9, 2009

Name: Heavy Snow in Washington, March 9, 2009
Start: 2009-03-09T05:00
End: 2009-03-09T21:00
Location: Washington

March 9, 2009 · NWS OTX · 2 events in 2 counties and zones

A cold and unstable low pressure system brought numerous moderate to heavy snow showers to the palouse and Spokane area. Several locations picked up between four to six inches of snow.

Where it happened

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.

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

Deaths: 0
Injuries: 0
Property damage: None recorded
Crop damage: None recorded
Events: 2

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.

A cold and unstable low pressure system brought numerous moderate to heavy snow showers to the palouse and Spokane area. Several locations picked up between four to six inches of snow. The heavy snow showers resulted in accumulations of an inch per hour which contributed to over 100 slide-offs and accidents in the Spokane area.

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 Mar 9, 3:53 AM PST, 1 hour 7 minutes earlier.

Area forecast discussion, Mar 9, 3:53 AM PST, 1 hour 7 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
453 AM PDT MON MAR 9 2009

.SYNOPSIS...
A STRONG ARCTIC COLD FRONT WILL SWEEP THROUGH WASHINGTON AND IDAHO
LATE TODAY. LOCALLY WINDY AND SNOWY CONDITIONS WILL ACCOMPANY THE
PASSAGE OF THE ARCTIC FRONT. MUCH COLDER TEMPERATURES ARE
EXPECTED BY TONIGHT AND RECORD LOWS WILL BE POSSIBLE TUESDAY
MORNING. MORE STABLE WEATHER IS EXPECTED TO ARRIVE ON BY TUESDAY
NIGHT AND CONTINUE THROUGH THE END OF NEXT WEEK.

&&

.DISCUSSION...

TODAY AND TONIGHT...SNOW ACCUMULATIONS WILL BE THE MOST DIFFICULT
FORECAST CHALLENGE TODAY AND TONIGHT. A HIGHLY CONVECTIVE AIRMASS
REMAINS OVER THE PACIFIC NORTHWEST THIS MORNING. 500MB
TEMPERATURES BETWEEN -38C AND -40C WILL CONTINUE TO CONTRIBUTE TO
DEEP INSTABILITY OVER THE REGION THROUGH LATE TONIGHT. ANOTHER
SHORTWAVE WILL MOVE THROUGH THE RESIDENT LONGWAVE TROUGH TODAY.
AS OF 09Z...WATER VAPOR IMAGERY SHOWED A WEAK CIRCULATION DIVING
DUE SOUTH INTO SOUTHERN BRITISH COLUMBIA. THE NAM AND GFS HAVE
COME INTO PRETTY GOOD AGREEMENT WITH THE TRACK AND SPEED OF THE
UPPER TROUGH TODAY AND TONIGHT. THE MODELS CONTINUE TO HAVE
DIFFERENCES WITH THE POSITION AND PROGRESSION OF THE SURFACE LOW.
THE NAM MAY BE SLIGHTLY BETTER WITH THE ELONGATED AND DIFFUSE LOW
CENTER. BOTH MODELS FORECAST INCREASING ISENTROPIC ASCENT OVER THE
EASTERN THIRD OF WASHINGTON BETWEEN 12Z-18Z. GIVEN THE DESCENT
UPPER JET SUPPORT AND RELATIVELY WEAK OROGRAPHICS TODAY...VALLEYS
WILL PROBABLY EXPERIENCE SIMILAR PRECIPITATION AMOUNTS AS THE
MOUNTAINS. ACCUMULATIONS THIS TIME OF YEAR ARE VERY TOUGH TO
FORECAST IN A CONVECTIVE ENVIRONMENT...ESPECIALLY IN THE LOW
ELEVATIONS. PLACES LIKE SPOKANE...DEER PARK...AND COLVILLE WILL
HAVE A CHANCE AT ACCUMULATIONS UP TO AN INCH THIS MORNING BEFORE
TEMPERATURES APPROACH FREEZING THIS AFTERNOON. I WILL HOLD OFF ON
ISSUING ANY ADVISORY FOR THE DAYLIGHT HOURS SINCE THERE IS A GOOD
CHANCE OF MELTING THIS AFTERNOON. HOWEVER...AS THE SURFACE LOW
CROSSES THE IDAHO PANHANDLE OVERNIGHT...1 TO 3 INCH ACCUMULATIONS
LOOK TO BE A GOOD BET FOR SPOKANE...COLVILLE...SANDPOINT...
KELLOGG...AND POSSIBLY IN PULLMAN. A WINTER WEATHER ADVISORY HAS
BEEN POSTED FOR THE AFOREMENTIONED COMMUNITIES STARTING AT 8PM AND
GOING THROUGH TUESDAY MORNING.

MODIFIED ARCTIC AIR HAS ALREADY BEGUN TO BLEED THROUGH THE
OKANOGAN VALLEY. AS OF 09Z...THE SURFACE DEWPOINT AT OMAK WAS 8F.
THE REAL SURGE OF BITTERLY COLD AIR WILL OCCUR TONIGHT AS THE
SURFACE LOW PULLS EAST INTO THE IDAHO PANHANDLE. A STRONG SURFACE
PRESSURE GRADIENT STRADDLING THE CANADIAN BORDER SUGGESTS WINDY
CONDITIONS TONIGHT IN THE OMAK AREA AND OVER THE WATERVILLE
PLATEAU. WIND CHILLS WILL LIKELY FALL BELOW ZERO AFTER MIDNIGHT
AND REMAIN BELOW ZERO THROUGH TUESDAY MORNING. /GKOCH

...UNSEASONABLY COLD TEMPERATURES EXPECTED FOR TUESDAY
THROUGH THURSDAY WITH RECORD LOWS POSSIBLE WEDNESDAY AND
THURSDAY. HIGH TEMPERATURES WILL BE 15-25 DEGREES BELOW NORMAL FOR
THIS TIME OF YEAR...

TUESDAY...THE SFC LOW AND ASSOCIATED UPPER-LEVEL TROUGH
AXIS WILL BE EXITING EAST INTO WESTERN MT AND A DRY..COLD ARCTIC
AIRMASS WILL BE LEFT ACROSS THE CWA IN ITS WAKE. 00Z NAM/GFS IN
GENERALLY AGREEMENT ON THE INTENSITY OF THE AIRMASS WITH 850MB
TEMPERATURES ALONG THE NORTHERN PERIPHERY OF THE CWA AVERAGING
-16C AND ONLY WARMING TO -13C SOUTH NEAR THE OR BORDER. MIXING
THIS DRY ADIABATICALLY FROM 850MB WILL YIELD HIGHS ON THE ORDER OF
15-25 DEGREES BELOW SEASONAL NORMALS...YET OUR FORECAST REMAINS
ON THE WARMER SIDE OF SOME OF THE GRIDDED GUIDANCE INCLUDING THE
GFS40/NAM12 WHICH POSE HIGHS IN THE UPPER TEENS ACROSS THE
NORTHERN VALLEYS INCLUDING SPOKANE.  THIS IS IN LARGE PART TO
ACCOUNT FOR THE MODERATE BL MIXING FROM THE LINGERING SFC
GRADIENT...ABUNDANT SOLAR INSULATION UNDER CLEAR SKIES...AND
INFLUENCE OF SOME OF THE WARMER GUIDANCE.  THE LIGHT TO
BREEZY WINDS WILL ALSO PRODUCE WINDCHILLS ACROSS THE
OKANOGAN VALLEY...WATERVILLE PLATEAU...PURCELL TRENCH...AND
EAST SLOPE VALLEYS BELOW ZERO BEFORE WINDS SUBSIDE TUESDAY NT.

TUESDAY NT...THIS IS EXPECTED TO BE THE COLDEST NIGHT OF THE
WEEK AS SFC GRADIENTS RELAX AND SKIES REMAIN GENERALLY CLEAR.
RECORDS FOR MARCH 11 TELL US THAT RECORDS WILL BE MET WITH EASE
IF THE FORECAST LOWS ARE TO PAN OUT...MOS GUIDANCE HAS BEEN
DROPPING LIKE A ROCK DURING THE LAST 48 HRS AND IT LOOKS LIKE WE
ARE ON THE RIGHT TRACK STAYING A FEW DEGREES COLDER. FOR
EXAMPLE...NAM MOS GUIDANCE FOR KGEG DROPPED FROM 11F TO 3F FROM
THE 12Z TO 00Z PACKAGE. ADDITIONALLY...RECORD LOWS ARE NOT
EXCEPTIONALLY COLD FOR THE DATE WITH KGEG 7F...KPUW 4F...KLWS
18...AND KEAT 19F.

WEDNESDAY AND THURSDAY...EXPECT A GRADUAL WARMING TREND
AND DRY CONDITIONS. THIS IS OVERWHELMING AGREEMENT AMONGST
THE GFS/ECMWF/GEFS MEAN THAT THE APPROACHING RIDGE AXIS WILL
REMAIN FIXED AT 130W KEEPING A COOL NW FLOW ACROSS
EASTERN WA AND NORTHERN ID RESULTING IN 850MB TEMPERATURES
BETWEEN -3 TO -10C. TEMPERATURES WILL REMAIN BELOW SEASONAL
NORMALS. MORNING LOWS WEDNESDAY NT/THURSDAY WILL FLIRT WITH
RECORDS ONCE AGAIN ACROSS THE EASTERN ZONES WHERE THE AIRMASS
WILL REMAIN THE COLDEST AND SFC GRADIENTS REMAIN WEAK. /BODNAR

&&

.AVIATION...
BANDS OF SNOW ARE EXPECTED TODAY AND TONIGHT OVER THE IDAHO
PANHANDLE AND OVER THE EASTERN THIRD OF WASHINGTON. SNOW SHOWERS
WILL LIKELY BE THE MOST CONCENTRATED IN THE SPOKANE...PULLMAN AND
COEUR DALENE AREAS BETWEEN 14Z AND 19Z AHEAD OF AN UPPER LEVEL
SHORTWAVE TROUGH. A BREAK IN THE SNOW SHOWERS WILL BE POSSIBLE THIS
AFTERNOON AND EARLY THIS EVENING. THEN ANOTHER ROUND OF HEAVY SNOW
SHOWERS WILL BE POSSIBLE AFTER 06Z AS THE SURFACE FRONT MOVES
THROUGH THE CENTRAL IDAHO PANHANDLE. IFR CEILINGS AND VISIBILITIES
CAN BE EXPECTED WITH THE HEAVIER SNOW SHOWERS. MOUNTAIN OBSCURATIONS
WILL ALSO BE COMMON THROUGH AT LEAST 12Z TUESDAY IN THE
PANHANDLE...NORTHEAST WASHINGTON MOUNTAINS...AND OVER THE CASCADES.
/GKOCH

&&

.PRELIMINARY POINT TEMPS/POPS...
SPOKANE        32  12  21   1  30  16 /  60  70  20   0   0   0
COEUR DALENE  29  12  18   0  29  17 /  70  70  20   0   0   0
PULLMAN        32  16  25   9  31  13 /  50  70  20   0   0   0
LEWISTON       38  25  29  16  39  21 /  30  50  20   0   0   0
COLVILLE       34  11  22  -2  32  17 /  70  70   0   0   0   0
SANDPOINT      28  12  17  -3  31  11 /  70  70  10   0   0   0
KELLOGG        31  16  19  -2  28   8 /  70  90  30  10   0  10
MOSES LAKE     41  16  27  11  39  20 /  30  20   0   0   0   0
WENATCHEE      39  16  28  12  38  23 /  30  20   0   0   0   0
OMAK           34   8  21  -1  38  18 /  50  20   0   0   0   0

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...     WINTER WEATHER ADVISORY FROM 8 PM THIS EVENING TO 5 AM PDT
     TUESDAY FOR COEUR DALENE AREA...IDAHO PALOUSE.

     WINTER WEATHER ADVISORY FROM 8 PM THIS EVENING TO 5 AM PDT
     TUESDAY FOR NORTHERN PANHANDLE.

     WINTER WEATHER ADVISORY FROM 8 PM THIS EVENING TO 8 AM PDT
     TUESDAY FOR CENTRAL PANHANDLE MOUNTAINS.

WA...WINTER WEATHER ADVISORY FROM 8 PM THIS EVENING TO 5 AM PDT
     TUESDAY FOR SPOKANE AREA...WASHINGTON PALOUSE.

     WINTER WEATHER ADVISORY FROM 8 PM THIS EVENING TO 5 AM PDT
     TUESDAY FOR NORTHEAST MOUNTAINS.

&&

Hazardous weather outlook, Mar 8, 3:17 PM PST, 13 hours 43 minutes before

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE SPOKANE WA
417 PM PDT SUN MAR 8 2009

IDZ001>004-026-027-WAZ031>033-036>038-092330-
NORTHERN PANHANDLE-COEUR DALENE AREA-IDAHO PALOUSE-
CENTRAL PANHANDLE MOUNTAINS-LEWISTON AREA-
LEWIS AND SOUTHERN NEZ PERCE COUNTIES-NORTHEAST BLUE MOUNTAINS-
LOWER GARFIELD AND ASOTIN COUNTIES-WASHINGTON PALOUSE-
SPOKANE AREA-NORTHEAST MOUNTAINS-OKANOGAN HIGHLANDS-
417 PM PDT SUN MAR 8 2009

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

.DAY ONE...THIS AFTERNOON AND TONIGHT

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

SIGNIFICANT SNOW AND BLUSTERY NORTH WINDS WILL BE POSSIBLE LATE MONDAY
THROUGH TUESDAY THAT WILL ACCOMPANY AN ARCTIC FRONTAL PASSAGE. IN
ADDITION...DANGEROUSLY LOW WIND CHILL READINGS CAN BE EXPECTED MAINLY
MONDAY NIGHT BEFORE WINDS BEGIN TO DECREASE TUESDAY. WITH LIGHT
WINDS EXPECTED BY TUESDAY NIGHT...RECORD LOW TEMPERATURES WILL BE POSSIBLE.

WAZ034-035-041>044-092330-
MOSES LAKE AREA-UPPER COLUMBIA BASIN-WENATCHEE AREA-
EAST SLOPES NORTHERN CASCADES-OKANOGAN VALLEY-WATERVILLE PLATEAU-
417 PM PDT SUN MAR 8 2009

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

.DAY ONE...THIS AFTERNOON AND TONIGHT

NO HAZARDOUS WEATHER IS ANTICIPATED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

ACCOMPANYING THE PASSAGE OF AN ARCTIC COLD FRONT MONDAY NIGHT WILL
BE BLUSTERY NORTH WINDS AND DANGEROUSLY LOW WIND CHILL READINGS. IN
ADDITION...RECORD COLD TEMPERATURES WILL BE POSSIBLE ESPECIALLY
TUESDAY NIGHT AFTER THE WINDS DECREASE.

The radar

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

Open the radar archive at this moment

Event by event

2 heavy snow. Local standard time, as filed.

Heavy Snow, Spokane Area

When: March 9, 5:00 AM PST to 9:00 PM PST
Where: Spokane Area forecast zone
Reported by: Trained Spotter
Coordinates: 47.599, -117.911 (the zone’s center; the record gives no point)

Heavy Snow, Washington Palouse

When: March 9, 5:00 AM PST to 9:00 PM PST
Where: Washington Palouse forecast zone
Reported by: Trained Spotter
Coordinates: 47.261, -117.463 (the zone’s center; the record gives no point)

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 Washington in 2009 Every state in 2009 This day in weather history Warnings in Washington, March 2009

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: 157580, 157581.