Another round of heavy snow impacted the |Cascades and the Olympics. Snow began affecting the mountains on the 18th, with several additional periods of heavy snowfall bringing additional accumulation through the 21st.
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.
Another round of heavy snow impacted the |Cascades and the Olympics. Snow began affecting the mountains on the 18th, with several additional periods of heavy snowfall bringing additional accumulation through the 21st.
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 18, 3:32 PM PST, 1 hour 28 minutes earlier.
Area Forecast Discussion
National Weather Service Seattle WA
332 PM PST Wed Dec 18 2019
.SYNOPSIS...A front will push into the region tonight, bringing
rain and mountain snow to the region. A stronger storm system with
more moisture will bring more rain and mountain snow on Thursday
evening through Friday.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY/...The leading edge of the
first frontal system is continuing to approach and very slowly
advance into Western Washington this afternoon. So far, more than
three-quarters of an inch of rain at Forks and Quillayute, but to
the south the line of heavier precipitation remains offshore. This
line with move east across the region tonight and into early
Thursday. Meanwhile, locally breezy conditions along the coast and
in the north interior this evening ahead of the front. Snow
levels gradually rise a bit, but the higher elevations of the
Olympics will see snow as the line moves onshore. Similarly, when
the precipitation reaches the Cascades later tonight, expect it to
be in the form of snow down below the passes. Latest guidance
continues to suggest a bit of a break in between the two frontal
systems during the day on Thursday, so do not be surprised to see
some time where it's not snowing in the mountains/raining in the
lowlands, but there might be a few light periods of precipitation
lingering at times and plenty of clouds will likely remain around.
However, the next system remains on track with an atmospheric
river push into the region from the southwest late Thursday
afternoon and evening. This will be a warmer system, so snow
levels will continue to rise across most of the region. At this
point, precipitation type will likely be snow down below the
Cascade passes at onset, but snow levels may rise above White and
Snoqualmie passes into early Friday as the easterly flow at the
Cascade crest weakens and diminishes. Confidence in the exact
timing of this warming remains somewhat lower, but regardless,
there will likely be a period of heavy snow before the snow level
lifts above the passes. As a result, the winter storm warnings for
the Cascades remain in effect and those planning to travel over
the passes should closely monitor the forecast and road conditions.
Meanwhile, widespread breezy conditions are expected Thursday
night into early Friday across the coastal areas and across the
interior north of around Whidbey Island.
The primary plume of moisture begins to shift south of the region
during the day on Saturday, but some showers will likely continue.
Snow levels will drop back down to near or below pass level on
early Saturday. However, any new snowfall at the passes will be
relatively minimal - on the order of a few inches- as the
moisture tapers off. Showers will likely be confined to the
mountain areas by late Sunday afternoon. Cullen
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...A generally cooler and
drier pattern looks to take shape early next week. Heights will
rise Monday and Tuesday as a weak upper ridge moves into the area.
Under high pressure, expect that low temperatures Tuesday and
Wednesday mornings will trend cooler, possibly returning to the
freezing mark in the lowlands Wednesday night, especially away
from the urban areas. Ensembles suggest a general troughing
pattern may redevelop by around midweek, so a weak impulse that
brings some precipitation at some point cannot be ruled out.
Nevertheless, the forecast was generally kept dry with only very
low mention of precipitation chances. Cullen
&&
.AVIATION...Active weather through the TAF period as a series of
systems move across the area. Rain along the coast currently will
slowly shift inland this afternoon into tonight. Cigs and visby will
deteriorate as this occurs with MVFR conditions likely tonight into
early Friday. A bit of a break in activity expected during the day
Thursday before heavy rain moves in from south to north from
Thursday afternoon into Friday. Breezy winds expected for the north
interior tonight into early Thursday and across the rest of the area
Thursday night into early Friday.
KSEA...VFR conditions continue this afternoon. MVFR likely later
this evening into Thursday morning as rain moves into the area. May
see a bit of improvement Thursday morning into Thursday afternoon
before conditions deteriorate again with heavy rainfall moving in
from the south. Southerly winds 5 to 12 kts, increasing Thursday
evening 10 to 20 kts. CEO
&&
.MARINE...A frontal system will continue to move across the coastal
waters and weaken. Gale strength southerlies will continue across
the coastal waters, the northern inland waters, and the east
entrance of the Strait of Juan de Fuca today. A series of fronts
will progress through the region Thursday into the weekend, likely
warranting additional headlines for the Western Washington waters.
CEO
&&
.HYDROLOGY...An atmospheric river will bring heavy rain later
Thursday through Saturday morning. Rainfall totals over the
mountains should generally be in the 3-6 inch range with local
amounts up to 8 inches or so. Totals for the lowlands will be
impressive as well, with 2-4 inches expected across many areas.
This combination could be enough to push some rivers above flood
stage late Thursday, with flooding concerns lasting into at least
Saturday. In addition to river flooding, some urban and small
stream flooding will be possible with these rainfall rates and
amounts. A slight landslide threat will also exist through the
weekend as a result.
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...Flood Watch from Thursday evening through Sunday evening for
Admiralty Inlet Area-Bellevue and Vicinity-Bremerton and
Vicinity-Cascades of Pierce and Lewis Counties-Cascades of
Snohomish and King Counties-Cascades of Whatcom and Skagit
Counties-Central Coast-East Puget Sound Lowlands-Eastern
Strait of Juan de Fuca-Everett and Vicinity-Hood Canal Area-
Lower Chehalis Valley Area-North Coast-Olympics-Seattle and
Vicinity-Southwest Interior-Tacoma Area-Western Skagit
County-Western Strait of Juan De Fuca-Western Whatcom
County.
Winter Storm Warning from 6 PM this evening to 6 AM PST Friday
for Cascades of Pierce and Lewis Counties-Cascades of
Snohomish and King Counties-Cascades of Whatcom and Skagit
Counties.
Winter Weather Advisory from 10 AM to 10 PM PST Thursday for
Olympics.
Winter Storm Watch from late Thursday night through Saturday
morning for Olympics.
PZ...Small Craft Advisory until 4 PM PST Thursday for Admiralty Inlet-
Grays Harbor Bar.
Small Craft Advisory from 10 PM this evening to 4 PM PST
Thursday 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.
Gale Warning until 10 PM PST this evening 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.
Small Craft Advisory from 2 AM to 4 PM PST Thursday for East
Entrance U.S. Waters Strait Of Juan De Fuca-Northern Inland
Waters Including The San Juan Islands.
Gale Warning until 2 AM PST Thursday for East Entrance U.S.
Waters Strait Of Juan De Fuca-Northern Inland Waters
Including The San Juan Islands.
Small Craft Advisory until 10 PM PST this evening for West
Entrance U.S. Waters Strait Of Juan De Fuca.
&&
www.weather.gov/seattle4 heavy snow. Local standard time, as filed.
Heavy snow affected the Olympics mountains, beginning during the evening hours of the 18th and continuing through the 21st. Snowfall measurement data was intermittent through the event, with estimated new storm total snowfall accumulation of around 30 inches.
Snow began falling in the southern Cascades on the evening of the 18th and lingered a little than the northern and central Cascades, with snowfall accumulation ending on the evening of the 23rd at Mount Rainier National Park. New total snowfall accumulation of around 22 inches. Less snowfall was observed at White Pass, with new storm total snowfall amounts less than 10 inches.
Snow began to affect the central Cascades late in the evening on the 18th and continued into the afternoon hours of the 21st. Snow affected the Passes during this event, bringing new storm total snowfall amounts of around 27 inches to Stevens Pass and around 14 inches to Snoqualmie Pass. Snow ended at Snoqualmie Pass earlier than it did Stevens, with little additional accumulation after the morning of the 20th as temperatures rose above freezing.
Snow began falling during the late evening hours of the 18th and continued through the afternoon hours of the 21st. New storm total snow accumulation of around 40 inches was reported.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Washington in 2019Every state in 2019This day in weather historyWarnings in Washington, December 2019
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: 869754, 869753, 869752, 869751.