An abnormally moist warm front resulted in heavy snowfall from the Upper Columbia Basin, into the Spokane Area, and up into the Northeast Mountains. Moisture content with this system was on the order of 180 to 200 percent of what is normally observed for the period this system moved through.
Every event with a place to put it; 3 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 OTX wrote it up.
An abnormally moist warm front resulted in heavy snowfall from the Upper Columbia Basin, into the Spokane Area, and up into the Northeast Mountains. Moisture content with this system was on the order of 180 to 200 percent of what is normally observed for the period this system moved through. A combination of good jet dynamics and strong isentropic ascent provided strong lifting mechanisms for periods of moderate to heavy snowfall rates during the early morning hours on Monday the 7th, which resulted in treacherous driving conditions for commuter traffic.
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 Jan 6, 4:06 PM PST, 3 hours 24 minutes earlier.
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
406 PM PST Sun Jan 6 2013
.SYNOPSIS...
Isolated to scattered snow showers will be possible late this
afternoon and early this evening behind an exiting weather
disturbance across the region. Beginning tonight the region will
go into a wet and unsettled weather pattern that will last through
mid week. An approaching storm system is expected to bring
widespread accumulations to eastern Washington and northern Idaho
late tonight into Monday. The Monday precipitation may change to
rain in places like Pullman, Ritzville, and Spokane. Cooler
weather will likely return to the region by late week.
&&
.DISCUSSION...
Tonight and Monday...An upper level low will exit the
region...while another moves through the Gulf of Alaska this
afternoon. This will result in weak ridging over the Inland
Northwest tonight and allow a 150kt plus westerly jet to move
into central British Columbia tonight...nosing into northern
Washington tomorrow. This jet has tapped into a nice moisture feed
with satellite estimates well over an inch. Model PWATs feeding
off the moisture tap will be in the range of .70 to .80 of an inch
which is 180-200 percent of normal. So definitely this will be a
juicy system.
Warm frontal lift will move east of the Cascades after 06z and is
rather weak at first but will increase in intensity through the
night. Westerly mid and upper level flow will allow slop over
precipitation across the Cascade crest but shadow most places
below the crest. Westerly flow will also focus precipitation
across the northern and central Panhandle mountains. All the
models are similar showing a short wave disturbance brush my
northeast zones after 18z Monday...about the same time the left
front exit region of the upper level jet moves close to the same
position. This will result in about 6 hours or so of moderate to
locally heavy precipitation across mainly the eastern 2/3s of my
CWFA. All areas will receive precipitation with the basin getting
around two tenths and the mountains ranging anywhere from a
quarter to over a half inch of liquid.
The challenge for the next 24 hours then will be precipitation
type. The surface gradient will increase out of the southwest
early Monday morning resulting in moderate to strong warm air
advection. Snow levels will begin near the surface at all areas
except for the L-C valley. However snow levels will rise through
the afternoon on Monday when the heaviest precipitation is
expected. At this time it all of the northern and central
Panhandle mountain valleys will remain as snow...with snow turning
over to rain from south to north from the basin to north of
highway 2 through the afternoon. At this time it appears there
will be enough snow accumulations for the northeast and Panhandle
mountain valleys to support a snow advisory. For the Spokane-Coeur
D'Alene areas south into the Palouse it looks like we will be a
little short of advisory criteria. This of course will have to be
monitored tonight and tomorrow as a degree or two difference in
temperature either way could mean the difference to an extended
period of heavier snow or snow turning over to rain earlier then
expected. /Tobin
Monday night through Wednesday: A dynamic upper level trough of
low pressure will impact the region Tuesday through Wednesday
night. This wave is located out in the north-central Pacific at
roughly 170W longitude. Out ahead of this wave will be a
strengthening upper level jet streak of 190+ kts. This jet streak
will help to amplify the pattern as this wave moves closer to the
west coast with the trough digging across the Gulf of Alaska. This
process will result in a strong vorticity maximum that develops at
the base and along the leading edge of the trough. The strong
dynamics at upper levels will result in a surface low that spins up
at 140W longitude and between 40N and 50N latitude. This
cyclogenesis will be aided by the right entrance region of the jet
streak forming out ahead of the upper level wave. Strong
baroclinicity will take lace with a warm frontal band pushing
northeast into the region by Tuesday. This will result in strong
isentropic ascent across the region with snow levels surging upwards
with the warm front. Low level flow will start out south to
southeasterly into the east slopes of the Cascades on Tuesday. This
should result in good upslope into this area with moderate
precipitation rates possible. Precipitation type will start out as
snow in the valleys and then transition to rain into Tuesday night
from south to north. Valleys further north, such as the upper Methow
Valley and over into the Okanogan Highlands, could see some heavy
snowfall accumulations before snow transitions over to rain.
Further to the east, the heaviest precipitation amounts will be
across the Northeast Mountains and into the Northern Panhandle.
There is some disagreement between models as far as how much
theses areas will actually get with the ECMWF being the drier
model compared to the GFS and NAM. The GFS and NAM have had a
wetter bias through the winter season with the ECMWF model
verifying better; thus, I decided to go a bit more conservative
with my QPF amounts in these areas. However, if the GFS or NAM
verifies better, than the northern mountains and valleys will see
much more precipitation than what is in the forecast. Snow levels
will be rising into Tuesday night, so precipitation will start out
as snowfall before transitioning over to rain as well. The far
northern valleys will see the highest snowfall totals, and will
see a decent chance at some heavy snowfall accumulations depending
on how fast the warmer air intrudes into this area.
A trailing cold front will push east across the region on
Wednesday with strong cold air advection expected with the front.
Precipitation across the region will transition from a stratiform
to a more convective regime behind the cold front with the cold
core of the upper level trough over the region. The best chances
for showers will likely be in the Idaho Panhandle on Wednesday.
The surface low will push into southern Alberta and continue to
deepen as it does so. This will result in a fairly good pressure
gradient across the region for Wednesday, but this gradient will
be weakening through Wednesday afternoon into Wednesday evening.
With lower levels of the atmosphere becoming more unstable, I
expect some breezy winds on Wednesday as stronger winds aloft mix
down to the surface. Temperatures will be relatively mild through
this period with highs in the the mid to upper 30s in the valleys
and lows only down into the low to mid 30s for Tuesday night. /SVH
Thursday and Friday: A cold front clears the Inland Northwest
early Thursday with only a few snow showers lingering through
Thursday morning. The surface TROF axis finally moves through the
region and allows a cold arctic airmass to establish itself. This
cold airmass and impressive long wave TROF will be the main story
through the remainder of the week with below average temperatures
likely. A decent shortwave embedded in the northwest flow aloft
will eventually bring another good chance of snow to the region
but not until the early part of the weekend.
Overall for this time period...backed off on the chances of
precipitation while dropping temperatures as confidence grows in
the break between shortwaves coupled with the unusually cold
air mass.
/AB
Saturday and Sunday...Continued cold through the weekend, with the
potential for more snowfall. Large scale trough should be well
established over the western two thirds of the country. What gets
interesting for the Inland Northwest is a well developed shortwave
that drops over the Pacific Northwest in the north to northwest
flow. With this so far out, chances for pops were kept near climo.
However, the extended models are all showing this wave, with some
timing and location differences. With a good moisture fetch with
this system and very cold air in place, the potential is there for
accumulating snowfall.
As far as temperatures go, went ahead and continued a slight
downward trend. Snow levels will be such that almost anything that
falls will be frozen and white, with snow even over the lowest
valley floors. Ty
&&
.AVIATION...
00Z TAFs: A few snow showers will linger over the region early this
evening as an upper level trough exits the region. This has been
resulting in rapid decreases in cigs/VSBYS for short periods of
time. Southwest winds will continue to to keep cigs/VSBYS MVFR/IFR
through 06-09z. More important though will be the next storm system
that will move into the area 06z tonight. this will spread light
snow across the region over night keeping conditions IFR through 12z
or so. Heavier snow will come through later in the morning and will
drop conditions IFR/LIFR through early afternoon. Accumulations
anywhere from an inch or less at KEAT/KMWH to 2-4 inches at
KGEG-KCOE will be possible. Snow will try to turn over to rain at
KMWH 15-17z...KPUW 17-18z and at KGEG-KSFF around 20-21z.
Precipitation decreasing from the west after 20z. /Tobin
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 27 34 29 38 34 38 / 70 100 40 80 70 60
Coeur d'Alene 28 34 30 37 33 37 / 70 100 50 90 70 70
Pullman 28 37 32 41 35 40 / 50 100 50 70 50 80
Lewiston 32 42 36 46 39 45 / 30 80 20 60 30 70
Colville 28 34 29 39 34 36 / 70 100 40 90 80 60
Sandpoint 28 32 31 38 35 37 / 70 100 60 90 100 90
Kellogg 27 32 29 37 34 36 / 70 100 90 100 100 100
Moses Lake 28 36 30 39 36 43 / 40 70 10 40 30 40
Wenatchee 27 33 29 37 35 37 / 40 50 10 60 40 40
Omak 26 32 26 36 33 35 / 60 80 10 70 70 40
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Winter Weather Advisory from 10 PM this evening to 10 PM PST
Monday for Central Panhandle Mountains-Northern Panhandle.
WA...Winter Weather Advisory from 10 PM this evening to 10 PM PST
Monday for Northeast Mountains.
&&HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE SPOKANE WA 702 AM PST SUN JAN 6 2013 IDZ001>004-WAZ033-035>038-071500- NORTHERN PANHANDLE-COEUR D'ALENE AREA-IDAHO PALOUSE- CENTRAL PANHANDLE MOUNTAINS-WASHINGTON PALOUSE- UPPER COLUMBIA BASIN-SPOKANE AREA-NORTHEAST MOUNTAINS- OKANOGAN HIGHLANDS- 702 AM PST SUN JAN 6 2013 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTH IDAHO... EAST CENTRAL WASHINGTON...NORTH CENTRAL WASHINGTON...NORTHEAST WASHINGTON AND SOUTHEAST WASHINGTON. .DAY ONE...TODAY AND TONIGHT SNOW WILL DECREASE THIS MORNING OVER THE IDAHO PANHANDLE. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY ANOTHER ROUND OF SNOW IS EXPECTED ON MONDAY. ACCUMULATIONS IN THE 2 TO 4 INCH RANGE ARE EXPECTED IN THE SPOKANE...COEUR D'ALENE... KELLOGG...DAVENPORT...AND REPUBLIC AREAS. AMOUNTS OF 3 TO 6 INCHES WILL BE POSSIBLE AROUND COLVILLE...SANDPOINT...AND PRIEST LAKE. THE HEAVIEST SNOW WILL LIKELY FALL MONDAY MORNING INTO EARLY MONDAY AFTERNOON. WAZ042-071500- EAST SLOPES NORTHERN CASCADES- 702 AM PST SUN JAN 6 2013 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTH CENTRAL WASHINGTON. .DAY ONE...TODAY AND TONIGHT LIGHT SNOW IS EXPECTED TO BEGIN LATE TONIGHT OVER THE EAST SLOPES OF THE NORTHERN CASCADES. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY SNOW AMOUNTS IN THE 2 TO 4 INCH RANGE ARE EXPECTED FOR THE COMMUNITIES OF LEAVENWORTH...PLAIN...MAZAMA...TWISP AND WINTHROP BY LATE MONDAY MORNING. WAZ034-041-043-044-071500- MOSES LAKE AREA-WENATCHEE AREA-OKANOGAN VALLEY-WATERVILLE PLATEAU- 702 AM PST SUN JAN 6 2013 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL WASHINGTON...EAST CENTRAL WASHINGTON AND NORTH CENTRAL WASHINGTON. .DAY ONE...TODAY AND TONIGHT LIGHT SNOW IS EXPECTED TO DEVELOP PRIOR TO SUNRISE ON MONDAY. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY AN INCH OR TWO OF SNOW IS EXPECTED IN THE WENATCHEE...OMAK... CHELAN...AND REPUBLIC AREAS BY LATE MONDAY MORNING. IDZ026-027-WAZ031-032-071500- LEWISTON AREA-LEWIS AND SOUTHERN NEZ PERCE COUNTIES- NORTHEAST BLUE MOUNTAINS-LOWER GARFIELD AND ASOTIN COUNTIES- 702 AM PST SUN JAN 6 2013 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTH CENTRAL IDAHO AND SOUTHEAST WASHINGTON. .DAY ONE...TODAY AND TONIGHT HAZARDOUS WEATHER IS NOT EXPECTED. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY ON MONDAY MORNING...SNOW ACCUMULATIONS IN THE 1 TO 3 INCH RANGE ARE ANTICIPATED ABOVE 2000 FEET AROUND WINCHESTER...PEOLA...AND ALPOWA SUMMIT.
The national radar mosaic for the moment the first event began.
3 heavy snow. Local standard time, as filed.
Storm total snowfall reports of four to over five inches were common across the area.
Numerous heavy snowfall reports of five to seven inches were observed around and south of the Colville area. Snowfall reports were a bit lighter closer to the Canadian border in the range of two to three inches.
Storm total snowfall reports of five to six inches were common across the area. Dozens of schools were closed for the morning of the 7th, and numerous slide offs and accidents were reported as the heavy snowfall resulted in a messy morning commute. A major trouble spot was on Interstate 90 at the Argonne exit where a tanker truck driving west bound jacked-knifed. Multiple vehicles, including a Spokane Transit Authority (STA) bus, collided into the semi-truck. Traffic was restricted to only the right lane for at least an hour between 0530PST and 0630PST.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Washington in 2013Every state in 2013This day in weather historyWarnings in Washington, January 2013
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: 427438, 427428, 427434.