Brier Weather Station
Latitude N 47° 46' 49" Longitude W 122° 16' 48" Elevation 341 ft
773
FXUS66 KSEW 102202
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
302 PM PDT Tue Mar 10 2026
.SYNOPSIS...
Active weather continues, with a stout front on the way tomorrow
evening, lasting into Thursday morning. Additional systems are
poised to move through the region through the weekend, with
heavy mountain snow and lowland rain expected through this time
period. A threat of river flooding remains in the forecast for
areas south of Olympia.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
A wave of showers is beginning to make its way into Puget Sound
this afternoon. Given the snow levels and present temperatures,
this should fall as rain for lowland locations, with some light
snow in the Cascades by the time it gets there.
A strong cold front will approach the area tomorrow, driving up
the winds by the late morning, peaking late Wednesday into early
Thursday morning. Blizzard warnings in the Cascades and Olympics
remain intact, but the wind forecast for lowland locations also
increased. Winds in the Cascades are still forecast to gust
between 35 and 45 mph, but with the 850 mb winds also indicating
50-55 mph winds, high elevation locations could gust higher than
that. Additionally, wind advisories have been posted to begin
Wednesday afternoon and last through Thursday morning. Winds
will begin as strong southwesterly winds, and for areas north of
Everett, expect a transition to strong northwesterly winds in
the late evening as a strong push occurs through the Strait of
Juan de Fuca. Areas south of Everett will remain southwesterly.
At the onset of this event, snow levels are forecast to rise to
around 5000-6000ft before coming back down late Wednesday night
into Thursday morning. During the period where the snow levels
are higher, expect a period of rain in the Cascade passes on top
of whatever snow has fallen. Temperatures will cool overnight
for concerns of re- freezing over the roadways. Travel
conditions could be very difficult with all of these factors
combined.
QPF amounts in lowland locations will be between 1.5 to 3 inches
through Friday for areas from Seattle south, with around a half
to one inch in areas north of the metro. The higher amounts are
forecast for the Chehalis Valley, where some area rivers are
forecast to rise into minor flood stages.
After these hazards begin to taper off early Thursday morning,
mountain showers will continue into Friday.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
Heavy snow is expected to continue on Friday into the weekend,
and Winter Storm Watches remain posted for the late week/weekend
period. Snow levels remain around 2500 feet or less. By
Saturday, area snow levels drop below 1000 feet, so depending on
moisture availability, there is also a chance for some of the
higher hills amidst the lowland locations to receive a dusting
of snow come Saturday morning.
Forecast guidance is still holding onto another potential
atmospheric river coming overtop a building ridge to the south
of the Pacific Northwest on Sunday into Monday. Right now it`s
too early to tell how much rain will fall from this system, but
confidence is elevated in wet conditions lingering into early
next week before the influence of the ridge may become more
apparent.
21
&&
.AVIATION...
Mostly VFR this afternoon with pockets of MVFR cigs. A frontal
system will continue to progress inland through this evening,
bringing widespread shower activity, chances for a few lightning
strikes, and breezy winds up to 25-30 kt along the front. Flight
conditions will continue to lower tonight with widespread MVFR, with
potential for IFR conditions to develop overnight into Thursday
morning. More stratiform rain and snow will develop across the
region Wednesday morning and lift northward, with another cold front
slated to cross the region Wednesday afternoon bringing widespread
gusty winds.
KSEA...VFR this afternoon, with increasing chances for MVFR ceilings
to develop this evening and overnight as shower activity continues.
A lightning strike or two is possible this afternoon, but confidence
is not high enough to include in the TAF. Southerly gusts will
continue this afternoon to 20-25 kt as a frontal system crosses the
region, with winds easing somewhat overnight. More steady rain will
move over the terminal Wednesday morning, maintaining MVFR
conditions with increasing potential for ceilings below 2000 feet
(40% to 50% chance) Wednesday morning. S/SW winds will increase
midday Wednesday with gusts briefly reaching 30-35 kt at the
terminal Wed afternoon.
15
&&
.MARINE...
Small Craft Advisories remain in effect for the Puget Sound,
Admiralty Inlet, and Salish Sea this afternoon and evening as a
frontal system progresses inland. SCAs for the coastal waters and
Grays Harbor bar remain in effect as well for westerly winds and
elevated seas. A much stronger storm system will move over the
region on Wednesday, with the potential to bring Gale Force winds to
all area waters. Gale Watches for the coastal waters and through the
Strait of Juan de Fuca have been upgraded to Gale Warnings, and Gale
Watches have been issued for the Puget Sound, Admiralty Inlet, and
Salish Sea for potential for gale strength gusts later on Wednesday.
A brief window of Storm Force gusts are also possible as hi-res
guidance is showing a moderate (30-50%) chance of them occuring over
the Central and Eastern Strait on Wednesday evening.
A weaker system will stall over the region Thursday and Friday. The
flow will turn northerly on Saturday, then offshore on Sunday as a
warm front moves into southern B.C.
Seas remain around 8-13 ft this afternoon before easing to around 7
to 9 feet overnight into Wednesday morning. Seas will briefly rise
as high as 15-18 feet across the coastal waters Wednesday afternoon
into early Thursday. Seas then ease to around 6 to 9 feet by
Thursday afternoon and remain below 10 feet thereafter.
15
&&
.HYDROLOGY...
Moderate to heavy precipitation over the Olympics this week will
cause the Skokomish River in Mason County to rise today with
flooding possible beginning early Thursday. The river will remain
high through the end of the week with additional crests forecast to
reach minor flood stage. Flooding is also possible on the Chehalis
river from Grand Mound to Grays Harbor, Newaukum River and
Skookumchuck River near Bucoda beginning Thursday. South Prairie
Creek also has potential to near minor flood stage on Friday. Crests
on these rivers will occur Friday into the weekend. Several other
rivers from Snohomish county southward are forecast to reach Action
Stage later this week. The lower snow levels with the atmospheric
river Thursday through Friday will make river forecasting tough
during this event. After a short break it is possible another
atmospheric river will move over the area early next week. With the
already high running rivers ahead of the event this will be closely
watched for another round of possible river flooding.
Felton/15
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...Wind Advisory from 3 PM Wednesday to 6 AM PDT Thursday for
City of Seattle-Downtown Everett / Marysville Area-
Eastern Kitsap County-Eastside-Foothills and Valleys of
Central King County-Foothills and Valleys of Pierce and
Southern King Counties-Foothills and Valleys of Snohomish
and Northern King Counties-Foothills and Valleys of
Thurston and Lewis Counties-Foothills and Valleys of the
North Cascades-Foothills of the Western and Southern
Olympic Peninsula-Island County-Lower Chehalis River
Valley-Lowlands of Lewis and Southern Thurston Counties-
Lowlands of Pierce and Southern King Counties-Lowlands of
Western Skagit and Northwestern Snohomish Counties-
Lowlands of Western Whatcom County-Middle Chehalis River
Valley-Northern Hood Canal-Olympia and Southern Puget
Sound-San Juan County-Shoreline / Lynnwood / South
Everett Area-Southern Hood Canal-Willapa and Black Hills.
Winter Weather Advisory until 6 PM PDT Wednesday for Cascades
of Pierce and Lewis Counties-Cascades of Snohomish and
Northern King Counties-Cascades of Southern King County-
Cascades of Whatcom and Skagit Counties.
Blizzard Warning from 6 PM Wednesday to 5 AM PDT Thursday for
Cascades of Pierce and Lewis Counties-Cascades of
Snohomish and Northern King Counties-Cascades of Southern
King County-Cascades of Whatcom and Skagit Counties-
Olympics.
Winter Storm Watch from late Wednesday night through late
Friday night for Cascades of Pierce and Lewis Counties-
Cascades of Snohomish and Northern King Counties-Cascades
of Southern King County-Cascades of Whatcom and Skagit
Counties-Olympics.
Flood Watch from Wednesday afternoon through Thursday
afternoon for Foothills of the Western and Southern
Olympic Peninsula-Middle Chehalis River Valley-Olympia
and Southern Puget Sound-Olympics-Southern Hood Canal-
Willapa and Black Hills.
Wind Advisory from 6 PM Wednesday to 6 AM PDT Thursday for
Eastern Strait of Juan de Fuca-Grays Harbor County Coast-
Northern Washington Coast-Port Townsend Area-Western
Strait of Juan de Fuca.
PZ...Small Craft Advisory until 5 PM PDT this afternoon for Grays
Harbor Bar.
Gale Warning from 2 PM Wednesday to 2 AM PDT Thursday for
Central U.S. Waters Strait Of Juan De Fuca-East Entrance
U.S. Waters Strait Of Juan De Fuca-West Entrance U.S.
Waters Strait Of Juan De Fuca.
Small Craft Advisory until 8 PM PDT this evening for Admiralty
Inlet-East Entrance U.S. Waters Strait Of Juan De Fuca-
Northern Inland Waters Including The San Juan Islands.
Gale Watch from Wednesday afternoon through late Wednesday
night for Admiralty Inlet-Northern Inland Waters
Including The San Juan Islands-Puget Sound and Hood Canal.
Small Craft Advisory until 11 PM PDT this evening for Puget
Sound and Hood Canal.
Small Craft Advisory until 11 AM PDT Wednesday 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 11 AM Wednesday to 2 AM PDT 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.
&&
$$
NWS SEW Office Area Forecast Discussion