A series of shortwaves tracked across Eastern Washington bringing several days of light to moderate snow fall. Snowfall was heaviest in mountains with amounts ranging from 10 to 20 inches.
Every event with a place to put it; 6 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.
A series of shortwaves tracked across Eastern Washington bringing several days of light to moderate snow fall. Snowfall was heaviest in mountains with amounts ranging from 10 to 20 inches. The low lands excluding Okanogan Valley received amounts ranging from 3 to 8 inches. Okanogan Valley and Okanogan Highlands were out of the high moisture areas and received only a couple of inches.
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 Nov 30, 10:19 PM PST, 1 hour 41 minutes earlier.
Area Forecast Discussion
National Weather Service Spokane WA
1019 PM PST Thu Nov 30 2023
.SYNOPSIS...
A significant pattern change develops late tonight and persist
through the weekend and beyond. Most locations will see several
rounds of snow through the weekend, before warmer air surges into
the region from the south. This will gradually turn all the snow
to rain, with only high elevation snow expected by early next
week. Snow amounts in the Cascades will be extremely heavy with
travel difficulties expected this weekend. Much warmer but wet
weather will continue through next week, with a significant snow
melt expected in the valleys.
&&
.UPDATE...
Made a few tweaks to the forecast for tonight through Saturday
based on latest radar trends and new 00Z model guidance.
Rest of tonight: Radar is picking up on the next round of snow
that is just beginning to push east of the Cascades with snow
falling in the Okanogan Valley, Wenatchee Area, Waterville Plateau
and Moses Lake Area. This batch of snow will be light with most
areas expected to see less than an inch of accumulation. I did
increase the precipitation probabilities up a little bit with most
areas seeing at least a 60% chance of a tenth of an inch. best
chances for snow at greater than 80% chance will come after 1000
PM this evening into the early morning hours across southeast
Washington and into the southern to central Idaho Panhandle. There
is generally a 30% chance that places like Pullman, Spokane, and
Coeur d'Alene will see at least an inch of snow by tomorrow
morning. Snow looks to be winding down right around the time of
the morning commute, but roads could be a bit slick and planning
on a little extra time for the commute is a good idea.
Saturday: I bumped up the winds a little bit over the Palouse to
the Spokane West Plains for Saturday morning into the early
afternoon. I expect we will see gusts in the 30 to 40 mph range
for this area. It's possible that with the additional snow
expected through the day Friday into Friday night that there will
be some patchy blowing and drifting snow with main concern being
along the Highway 2 corridor between Wilbur and Airway Heights and
also along Highway 195 south of Spokane to Pullman on the Palouse.
It's tough to say how impactful this threat is though as snow may
not be deep enough or light and dry enough to blow around all that
effectively. /SVH
&&
.DISCUSSION...
(Previous discussion sent at 457 PM November 30th)
...Extremely wet and snowy weather expected to develop beginning
Friday and persisting through next week...
Tonight through Saturday: Flurries will continue to fall
intermittently from the blanket of stratus overhead through this
evening until a steadier round of snow moves in later tonight.
The first of several shortwaves will track through the region
overnight, kicking off a multi-day event that will bring widespread
snowfall with particularly impressive accumulations in the
mountains. This first round tonight will drop around an inch of snow
for the eastern third of WA and the northern ID Panhandle, which
could make for a slick Friday morning commute.
The second round will arrive in central WA late Friday morning and
will scoot eastward from there, making it to eastern WA and northern
ID by Friday afternoon - just in time to create slick, snowy roads
for the evening commute in the Spokane Metro and surrounding areas.
Friday night into Saturday will feature the third round of snow,
which will likely produce higher snow amounts for the mountains than
the first two rounds. This round, like the last two, will move from
the Cascades eastward into the ID Panhandle. For Stevens Pass, the
heaviest snowfall rates (upward of an inch per hour) are expected
Friday night into early Saturday morning. Heaviest snow for Lookout
Pass will be later Saturday morning into Saturday afternoon.
All in all, the Cascade Passes will see three to four feet of snow
total by the time the weekend is over. Central WA lowlands will
accumulate 1 to 3 inches, eastern WA 2 to 6 inches, and northern ID
3 to 8 inches.
If you must travel over the mountain passes this weekend, check pass
reports beforehand, share your travel plans with friends and family,
pack an emergency supply kit, and make sure your vehicle is fully
winterized. /Fewkes
Sunday to Thursday: the Inland NW weather remains wet, while
temperatures start to warm above normal for many locations. This
means the pattern gradually changes from one dominated by snow to
one feature mainly mountain snow and lowland rain. Temperatures
will be warming through the period, peaking about 10 degrees above
normal on Tuesday. One frontal system moves through the region
Sunday, tapping an atmospheric river with PWATs around 0.70 or
200% of normal. This relatively quick moving system is lead in
with a warm front early in the day, with the cold front/upper
trough coming across the Cascades and heading toward the ID
Panhandle between mid-Sunday morning and early Sunday evening.
That moisture feeding into and along these features will bring
likely precipitation chances to most of the area through the day,
though chances will start to wane in the lee of the Cascades
through the middle to later afternoon. Then the best chances for
precipitation retreat into the mountains for Sunday night into
Monday morning.
* Precipitation amounts and type: Precipitation amounts are
forecast to be moderate to heavy in many places. In the
lowlands this translates to about 0.25 to 0.50 of liquid
precipitation, locally near 0.75 inches in lower elevations of
the ID Panhandle. A drier exception will be in the lee of the
Cascades and deeper Columbia Basin where some areas may not see
a tenth of an inch. The mountains will see around 0.75 to 1
inches of liquid equivalent precipitation, locally over 2
inches near the Cascade crest. The more complex part of the
forecast will be determining the precipitation types. With
PWATs numbers as described above (near 0.70), it becomes more
difficult to have all snow. The mountains, including the
passes, are expected to be mainly snow. However when you get
into some of the more southern passes, such as Blewett Pass, we
start to see some rain potential mix in. So what about
elsewhere? Models start to nose milder air into the region from
the south. Areas along and north of US-2, including much of the
Spokane Area, the higher Palouse and areas toward the
Waterville Plateau westward are expected to start off Sunday
with snow as the dominant precipitation type. South of there a
rain/snow mix or all rain is expected. Then models start nose
that warm air north through the day, leading to a transition to
a rain/snow mix or all rain. How quickly that occurs and how
far north is the more complex part. The northern zones, from
Okanogan County eastward to the Boundary and Bonner county, are
expected to hold onto air colder air longer and thus snow
remaining the more dominant precipitation type with this
system. (Places like the Methow Valley are one of those spots
that tends to hold onto colder air longer.) So these areas may
see the the potential for some moderate snow continuing.
Additional advisories may be needed. As for the mountains,
especially places like Steven and Lookout Pass some moderate to
heavy snow may be found around 4-10 inches.
* Winds: the day starts off relatively benign wind wise, but as
the cold front and upper trough start to push in through the
afternoon look for increasing winds. Peak winds are expected
around the mid-afternoon to early evening hours around the
Upper Columbia Basin to Palouse and Spokane/CdA area and
central Panhandle and near the Cascades, with speeds of 10-20
mph and gusts near 20-30 mph. Local gusts near 40 mph are
possible downwind of the Blue Mountains into the lower Palouse
in that period too.
Later Monday into Thursday a second system moves slowly through
the region, tapping an even wetter atmospheric river with PWATs
around 0.80-1.0 inches or 250-300% of normal. A deepening long-
wave trough sets-up over the eastern Pacific and amplifies a ridge
over the region. The leading warm front lifting into the region
Monday afternoon and it is not until Tuesday night into Wednesday
that the parent trough sends a shortwave into the region and
shifts a cold front into the region. Then Wednesday night into
Thursday additional shortwaves pivot into the region as the parent
trough continues to shift inland. So this set-up gives an overall
different focus from day-to-day. Precipitation chances start to
increase throughout the region Monday and gradually increases
Monday night into Tuesday and remains high through Wednesday and
Thursday. The details will continue to be fine-tuned as we get
more information with the complex and many-layered system. Overall
this system looks milder, with rain the much more dominant
precipitation type. That even includes places like Stevens and
Lookout Pass until later Wednesday into Thursday when the parent
trough starts inland and draws in some cooler air again. Through
the period between Monday and Thursday many areas could pick up
0.75 to 1 inches of precipitation, locally over 2 inches in the
mountains and over 4 inches near the Cascade crest. Mind you that
is over an 3.5 days, which breaks down to about a quarter to a
third of an inch a day in the lowlands and around a half to three-
quarters of an inch a day in the mountains, locally near 1.5
inches per day around the Cascade crest. With those amounts and
the milder air we will look toward hydrology concerns, with the
potential for rises on especially small streams and creeks and
ponding of water in urban and poor drainage areas or even debris
flows of mudslides in steeper terrain. Winds will remain breezy
Monday, with gusts near 15-20 mph. /Solveig
&&
.AVIATION...
06Z TAFs: A very active weather pattern expected through this
weekend. A weak weather system tonight will produce light snow
across the region through 15Z this morning with marginal VFR to
IFR conditions. There will be a brief break before a second round
of snow starts moving into EAT/MWH by 13-16Z and into GEG-SFF-COE-
PUW-LWS by 18-20Z. This second round is expected to bring a
period of moderate snowfall intensities. Lewiston airport will
see a transition to rain in the afternoon as temperatures warm up.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS: Confidence is high
for a period of light snow through Friday morning with MVFR to
IFR conditions. There's moderate to high confidence for snow
intensities to increase late Friday morning into Friday afternoon
with IFR to low IFR conditions. /SVH
Confidence descriptors:
Low - Less than a 30 percent chance
Moderate - 30 to 70 percent chance
High - Greater than a 70 percent chance
For additional probabilistic information for NWS Spokane airports,
please refer to the Aviation Dashboard on our webpage:
https://www.weather.gov/otx/avndashboard
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 22 32 26 37 28 44 / 80 90 70 80 40 90
Coeur d'Alene 24 32 27 37 28 43 / 80 90 80 90 40 90
Pullman 22 32 28 38 32 44 / 90 90 70 90 50 100
Lewiston 27 38 33 46 37 49 / 60 80 50 80 50 100
Colville 17 30 19 35 18 35 / 60 80 60 80 40 100
Sandpoint 23 30 25 35 25 38 / 80 90 80 90 40 100
Kellogg 25 33 30 36 31 43 / 90 90 90 100 50 100
Moses Lake 23 33 22 39 30 43 / 70 80 30 40 50 70
Wenatchee 25 33 26 39 30 38 / 70 80 50 60 50 80
Omak 24 32 25 40 27 38 / 50 70 50 70 40 80
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Winter Weather Advisory from 4 AM Friday to 4 PM PST Saturday
for Coeur d'Alene Area-Idaho Palouse-Lewis and Southern Nez
Perce Counties-Northern Panhandle.
Winter Storm Warning from 4 PM Friday to 4 PM PST Sunday for
Central Panhandle Mountains.
WA...Winter Weather Advisory from 4 AM Friday to 4 PM PST Saturday
for Northeast Mountains-Okanogan Highlands-Spokane Area-
Upper Columbia Basin-Washington Palouse-Waterville Plateau-
Wenatchee Area.
Winter Storm Warning from 4 AM Friday to 10 AM PST Sunday for
Northeast Blue Mountains.
Winter Storm Warning from 4 AM Friday to 4 AM PST Sunday for
Central Chelan County-Western Chelan County-Western
Okanogan County.
&&The national radar mosaic for the moment the first event began.
5 heavy snow, 1 winter weather. Local standard time, as filed.
Observer 2 miles south of Anatone recorded 9.3 inches of snow for December 1-4. December 1 received two tenths. Another 2.3 was added on December 2. December 3 received 5.8 inches. Another one inch was added on December 4.
Observer recorded 8 inches of snow for the period. The highest amount on December 2 with 5 inches. The other days saw one inch of snow. An observer recorded a 24 hour amount of 6.5 inches near Diamond Lake. The rest of the area had reports of 4 to 5 inches. Icy roads were attributed to fatal accident on US 385 milepost 231.7.
Observer estimated 7 inches of snow in Cashmere on December 2. Other reports in the area ranged from 2 to 5 inches. Observers in Wenatchee reported up to 5 inches. Manson had a report of 5 inches.
Observer reported 24.3 inches of snow 9 miles west of Lucerne. Another observer reported 19.5 inches 12 mile northwest of Lucerne.
Observer recorded 8.7 inches for the event. The highest 24 hour total 6 inches reported on December 2. The rest of the reports were an inch on the first, 1.5 inches on the third, and 0.2 inches on the fourth. The rest of the area had reports of 3 to 6 inches. A auto-pedestrian fatality was attributed to icy road conditions.
Prior to 7 AM, a 9-year-old was killed in a crash just south of Warden after the vehicle he was traveling in hit a patch of ice and spun off the roadway. The three other occupants sustained non-life-threatening injuries. An estimated 3 inches of snow was reported.
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, Northeast Mountains | 2023-12-01 | Outside/Open Areas | Indirect | ||
| Heavy Snow, Spokane Area | 2023-12-02 | Outside/Open Areas | Indirect | ||
| Winter Weather, Moses Lake Area | 2023-12-04 | 9 | Female | Outside/Open Areas | Indirect |
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Washington in 2023Every state in 2023This day in weather historyWarnings in Washington, December 2023
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: 1153990, 1154016, 1154052, 1154053, 1154018, 1154166.