Heavy snow fell in the Cascades.
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.
Heavy snow fell in the Cascades.
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 Jan 10, 3:15 PM PST, 1 hour 45 minutes earlier.
Area Forecast Discussion
National Weather Service Seattle WA
315 PM PST Wed Jan 10 2018
.SYNOPSIS...A storm system will bring active weather to the
region through Thursday evening. Expect rain, mountain snow with
windy conditions along the coast Thursday afternoon and evening.
Upper level ridging will begin to build into the area Friday
bringing drier conditions through the weekend. An active pattern is
expected to return next week with a series of systems forecast to
affect the area through mid week.
&&
.SHORT TERM...Light rain has begun to fall along the
coast this afternoon as a warm front begins to nudge into the
region. This will become fully established by late evening with the
heaviest precipitation expected to occur Thursday morning and
afternoon. Snow levels will rise to 3500 to 4000 feet for most of
the area by Thursday morning. Lower snow levels will linger over the
northern Washington Cascades, remaining in the 2000 to 2500 foot
range. Heaviest precipitation is expected over the mountains and
along the coast. The nominal snow levels will drive warning level
snow accumulations over the Cascades above 4000 feet in the south
and 2500 feet in the north. Similarly the Olympics will see advisory
level accumulations above 4000 ft. The relatively higher snow levels
over Olympics and Cascades South of Snohomish County will equate to
precipitation falling as rain below 3500 to 4000 ft and will result
in impacts to some area rivers flowing off the mountains in those
areas. A hydrologic outlook remains in effect, please see the outlook
or the hydrology section below for more details.
The surface low associated with this storm system will move into the
coastal waters Thursday afternoon and onto the North Coast Thursday
evening resulting in southwesterly winds rise to 20 to 30 mph with
gusts to 45 mph late in the afternoon and evening along the coast
and breezy to windy conditions elsewhere with gusts to 35 mph. A
wind advisory is in effect for the coast Thursday afternoon and
evening.
Upper level heights begin to build over the region by early Friday
morning setting the stage for drier more benign weather into the
weekend. Expect lingering showers particularly over the Cascades
Friday with snow levels around 3000 to 3500 feet.
.LONG TERM...Upper level ridging will continue to build over the
Pacific Northwest Saturday resulting in generally dry weather. A
weak system moving into British Columbia may result in some light
rain/showers along the north coast and North interior Saturday
morning. Otherwise expect a drying trend Saturday afternoon through
Sunday. Medium range models in pretty good agreement on bringing a
weak system into the area late Monday afternoon with a series of
systems expected to follow through at least mid week. Quite a bit
can change at this time range, however there is a fair amount of
confidence that a fairly active pattern will settle in beginning
early next week.
&&
.AVIATION...Westerly flow aloft will prevail tonight and Thursday.
A warm front will lift north through the area this evening. A
stronger frontal system will move through the area Thursday. An
associated deep but weakening surface low will make landfall on the
north coast early Thursday evening. The air mass is moist and
stable. There will be a mix of low and mid clouds tonight. MVFR low
clouds should become widespread on Thursday.
KSEA...MVFR low clouds should be prevalent tonight. Ceilings could
lower to IFR Thursday morning as heavier rain moves in.
Visibilities will likely be reduced at times Thursday in rain.
Southerly wind 4-8 knots will increase to 12-18 knots early Thursday
afternoon and become gusty. Schneider
&&
.MARINE...A warm front will lift north through the area this
afternoon and evening with small craft advisory strength southeast
winds over the Coastal Waters. A stronger frontal system will move
through the area Thursday with gales likely for the Coastal Waters
and small craft advisory strength winds most other waters.
Weak high pressure will move over the area Friday. A warm front will
lift through the area Friday night and Saturday morning. A weakening
cold front will approach the Coastal Waters from the west on Sunday
and fall apart over the area Sunday night. A stronger front will
approach from the west on Monday.. Schneider
&&
.HYDROLOGY...The frontal system that moves through the area Thursday
could drive a few rivers up toward flood stage--The Skokomish river
and White River at R street have forecasts up near flood stage.
Models have trended less on forecast precip amounts so other rivers
no longer have a significant chance of exceeding flood stage.
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...Winter Storm Warning from 10 PM this evening to 10 PM PST
Thursday for Cascades of Pierce and Lewis Counties-Cascades
of Snohomish and King Counties-Cascades of Whatcom and
Skagit Counties.
Wind Advisory from noon Thursday to midnight PST Thursday night
for Central Coast-North Coast.
Winter Weather Advisory from 10 PM this evening to 10 PM PST
Thursday for Olympics.
PZ...Small Craft Advisory for rough bar from 4 AM to 4 PM PST
Thursday for Grays Harbor Bar.
Small Craft Advisory until 4 AM 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 from 4 AM to 10 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.
Small Craft Advisory from 10 PM this evening to 4 AM PST Friday
for Central U.S. Waters Strait Of Juan De Fuca-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 Thursday for West Entrance
U.S. Waters Strait Of Juan De Fuca.
Small Craft Advisory from 10 AM Thursday to 4 AM PST Friday for
Puget Sound and Hood Canal.
&&
www.weather.gov/seattle3 heavy snow. Local standard time, as filed.
Stevens Pass got 12 inches in 12 hours on 1/11, 7 AM to 7 PM. Snoqualmie Pass got 19 inches in 24 hours 5 PM 1/10 to 5 PM 1/11. Alpental got 13 inches in 12 hous on 1/11, 6 AM to 6 PM.
Paradise got 18 inches in 24 hours from 7 PM on 1/10 to 7 PM on 1/11.
Mt. Baker got 12 inches in 12 hours on 1/11, 4 AM to 4 PM.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Washington in 2018Every state in 2018This day in weather historyWarnings in Washington, January 2018
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: 799295, 799296, 799294.