Active weather across Western Washington continued through the end of the month, with another storm system bringing a quick period of heavy snowfall to the Southern Cascades, including Mount Rainier National Park.
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 SEW wrote it up.
Active weather across Western Washington continued through the end of the month, with another storm system bringing a quick period of heavy snowfall to the Southern Cascades, including Mount Rainier National Park.
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 Seattle, WA wrote its last area forecast discussion before the first event at Dec 30, 3:43 AM PST, 3 hours 17 minutes earlier.
Area Forecast Discussion
National Weather Service Seattle WA
343 AM PST Thu Dec 30 2021
.SYNOPSIS...Weather system moving down from the northwest will
move through Western Washington this morning/early afternoon
bringing another round of snow to most of the area. Dry northerly
flow developing tonight and continuing through Friday. A warm
front will brush the area Saturday with temperatures warming up to
a within couple degrees of normal. System stalling over the area
Sunday and Sunday night before moving southeast Monday. Snow
levels lowering again Monday into Tuesday with the next system
moving inland south of the area.
&&
.SHORT TERM /TODAY THROUGH SATURDAY/...Doppler radar picking up
snow from about Seattle northward over the interior at 3 am/11z.
There was an area of enhanced precipitation over Snohomish county
but the echoes have weakened in the last hour. With a weak push of
southerly winds ahead of the system temperatures are in the lower
30s in the metro area for the 1st time since early on the 26th.
Temperatures around the remainder of the interior are mostly in
the 20s with the coast in the lower to mid 30s.
Upper level shortwave embedded in the northwesterly flow aloft
moving through Western Washington this morning into the early
afternoon hours with snow over the interior and snow or rain and
snow mixed along the coast. Shortwave will be south of the area by
late afternoon so have trimmed back the end time of the winter
weather advisory for the interior to 2 pm this afternoon. Snowfall
amounts still look to be in the 1 to 3 inches range with a little
higher amounts in the foothills. Have upgraded the Winter Weather
Advisory for the East Puget Sound Lowlands to a Winter Storm
Warning with 2 to 5 inches of new snow expected. Guidance warming
temperatures up above freezing from about Snohomish county
southward. This puff of southerlies ahead of the shortwave is
short lived and the winds in the lower levels turn back around to
northerly this afternoon. Cold air has been in place over the area
for awhile and will not be so easy to scour out. Have gone a few
degrees below guidance for the highs with high temperatures near
or below freezing from Seattle northward and in the mid or upper
30s in the Southwest Interior and along the coast.
Dry northerly flow aloft developing tonight. Fraser river outflow
winds returning to the Northwest Interior with Bellingham to
Williams Lake gradient dropping back down to -12 to -15 mb.
Outflow winds not as strong as the previous round. For now will
keep wind speeds just under advisory range with gusts to 40 mph.
While the precipitation will have come to an end tonight plenty of
low level moisture keeping some cloud cover in the area. Lows
tonight tricky with snow on the ground any clearing will allow the
temperatures to drop rapidly. With the cloud cover hanging around
over most of the area will keep lows in the 20s. Northwest
Interior the exception to this with a little more clearing
allowing temperatures to drop into the 12 to 18 degree range.
Break in the action Friday and Friday night with upper level
ridge nosing into British Columbia and dry northwesterly flow
aloft continuing across Western Washington. Fraser river outflow
winds easing with the Bellingham to Williams Lake gradient only
around -5 mb Friday afternoon. Highs will remain cool Friday, in
the upper 20s to mid 30s. Lows Friday night in the 20s except over
the Northwest Interior with teens likely.
Warm front brushing the area Saturday. Low level southerly winds,
925 mb winds in the 15 to 30 knots range, will erode the cold air
mass over the area "warming" afternoon temperatures to the upper
30s and lower 40s. Temperatures in the morning hours still near
freezing with snow levels outside of the coast near the surface.
Most of the model solutions keeping the precipitation from the
warm front north of the area but the front is close enough to
have chance pops throughout the day. For the morning hours that
will be a chance of light snow. In the afternoon rain or rain and
snow mixed.
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...Models and ensembles in
good agreement with the trailing cold front stalling over Western
Washington Sunday and Sunday night as the upper level trough
behind the front digs south over the Eastern Pacific. Cold front
moving through later Sunday night with another cool upper level
trough over the area Monday. Snow levels dropping down to near or
below 1000 feet. There are a significant number of ensemble
solutions on both the GFS and ECMWF that have snow for Monday,
especially in the morning. This will be something to watch out for
in future forecasts. Right now the blend solutions keep
temperatures warm enough for the precipitation to be in the form
of rain. Next system moving inland over Oregon Tuesday leaving
Western Washington on the cold side of the jet for another low
snow level scenario for the first week of the new year. Unsettled
pattern continues into Wednesday. Felton
&&
.AVIATION...Snow continues to spread across at this hour with accumulations over
the past 3 to 4 hours ranging from 1 to 3 inches across the region.
Snow will continue through the morning, likely tapering off from 18-
20Z today. Visibility will drop to 1 SM or less in bands of heavy
snow this morning. Southerly winds have increased, with most TAF
sites reporting sustained winds between 10-15 kts and occasional
gusts 20-25 kts. Winds will remain elevated through the remainder of
the morning before winds switch directions to to the north
and speeds gradually taper off this afternoon.
KSEA...Snow is increasing at the terminal once again at this
hour, with visibilities falling. Visibilities of 1 SM or less will
be common at times in this snow band, with additional
accumulations of 1 to 3 inches on top of the accumulations earlier
tonight. Snow will persist at the terminal through at least 18Z
this morning. Southerly winds have increased at the terminal with
sustained winds 10 to 15 kts and occasional gusts to around 20
kts. Expect gusty southerly winds to persist through the remainder
of the morning before winds flip and become northerly between
18-21Z today.
Pullin
&&
.MARINE...Southerly winds have increased across all waters, with
advisory level conditions being observed at this hour. Poor
visibility will be common through the remainder of the morning due
to snowfall, with visibilities of 1 SM or lower in any heavier
snow bands.
Behind the system, expect another round of Fraser outflow to develop
across the northern inland waters, with some gusty winds spilling
into the adjacent zones. A stronger system then arrives over the
weekend with another round of advisories likely.
Seas will continue to build to 10 to 13 ft through Thursday.
Additional hazardous swells will be possible again this weekend as
another stronger system approaches area waters.
Pullin
&&
.HYDROLOGY...River flooding not expected in the next 7 days.
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...Winter Weather Advisory until 2 PM PST this afternoon for
Admiralty Inlet Area-Bellevue and Vicinity-Bremerton and
Vicinity-Eastern Strait of Juan de Fuca-Everett and
Vicinity-Hood Canal Area-Lower Chehalis Valley Area-San
Juan County-Seattle and Vicinity-Southwest Interior-Tacoma
Area-Western Skagit County.
Winter Weather Advisory until 4 PM PST this afternoon for
Cascades of Pierce and Lewis Counties-Cascades of Snohomish
and King Counties.
Winter Weather Advisory until noon PST today for Cascades of
Whatcom and Skagit Counties.
Winter Storm Warning until noon PST today for Western Whatcom
County.
Winter Storm Warning until 2 PM PST this afternoon for East
Puget Sound Lowlands.
PZ...Small Craft Advisory until 4 AM PST Friday for Coastal Waters
From Cape Flattery To James Island 10 To 60 Nm-Coastal
Waters From Cape Flattery To James Island Out 10 Nm-Coastal
Waters From James Island To Point Grenville 10 To 60 Nm-
Coastal Waters From James Island To Point Grenville Out 10
Nm-Coastal Waters From Point Grenville To Cape Shoalwater
10 To 60 Nm-Coastal Waters From Point Grenville To Cape
Shoalwater Out 10 Nm-West Entrance U.S. Waters Strait Of
Juan De Fuca.
Small Craft Advisory until 10 AM PST Friday for Admiralty Inlet-
East Entrance U.S. Waters Strait Of Juan De Fuca-Northern
Inland Waters Including The San Juan Islands.
Small Craft Advisory until 4 PM PST this afternoon for Central
U.S. Waters Strait Of Juan De Fuca-Puget Sound and Hood
Canal.
&&
www.weather.gov/seattle1 heavy snow. Local standard time, as filed.
A quick period of heavy snow resulted in 12-13 inches of new snow at Paradise at Mount Rainier in a 12 hour period.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Washington in 2021Every state in 2021This day in weather historyWarnings in Washington, December 2021
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: 998622.