670
FXUS66 KSEW 011630
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
930 AM PDT Sat Nov 1 2025

.SYNOPSIS...A frontal system will move across Western
Washington today for continued rain and increased winds.
Showers linger into Sunday before another weak system possible
Monday into Tuesday. Unsettled conditions continue midweek to
late week with additional fronts.

&&

.SHORT TERM /TODAY THROUGH MONDAY/...The forecast is largely on
track this morning. The main focus is on rainfall accumulations
with possible river flooding in the Cascades - Flood Watched
remain in effect. Windy conditions this morning with gusty west
winds through the strait this afternoon. 33

Previous discussion...Stratiform precipitation continues
across Western Washington this morning as a frontal system over
the NE Pacific tracks towards Western Washington. The 06z
surface analysis from WPC shows the system located offshore of
central Oregon at 1008 mb. In general, the system will track
into the northern portions of the Olympic Peninsula this morning
and into southern BC by midday. South winds will increase
rapidly between 500-800 AM as the front approaches. HREF/REFS
continue to maintain a 40-80% chance of gusts exceeding 40 MPH
this morning over the majority of Western Washington,
particularly Skagit County southwards. Probabilities of gusts
over 50 MPH drop to less than 15% for most areas, peaking near
Grays Harbor County around 25-30%. The Wind Advisory remains in
place, with gusts of 35-45 MPH expected, and a few localized
gusts up to 50 MPH possible. Winds will peak between 800 AM to
1200 PM, for a brief period of gusty winds.

In addition to the inherited Wind Advisory, also issued a new
Wind Advisory for Western Whatcom County and San Juan Islands.
Despite the system moving through in less than 12 hours, more
uncertainty exists in the wind forecast for these locations.
This uncertainty can be seen quite well in the REFS spread. For
example at Bellingham, the 25th-75th spread in wind gusts is 6
MPH and 39 MPH.. a difference of 33 MPH. However, recent trends
in RRFS, as well as additional hi-res guidance (HRRR/NAM),
lends more confidence in potential stronger southerly winds for
portions of Whatcom & San Juan Islands. For this reason, issued
a Wind Advisory for these areas this morning. However, depending
on the boundary location as the system moves through, its very
possible there is a decent gradient in wind gust magnitude from
south-north for these areas.

Finally, on the wind side of things, UIL-BLI gradients will
increase fairly rapidly post-frontal, allowing for a stronger
push of west winds through the Strait of Juan de Fuca midday
through the afternoon. Westerly winds gusts may exceed 40 MPH
for portions of Admiralty Inlet and Whidbey Island during this
period. The Wind Advisory for these locations extends through
the afternoon (longer than other locations) given this wind
shift and increase. Localized tree limb damage and power
outages are possible today for Western Washington.

In addition to the wind, stratiform precipitation will continue
through this morning before the cold front slides through around
midday. Steadier precipitation will then taper to showers
around midday, with a convergence zone expected to develop over
Snohomish/King Counties later this afternoon and evening. Refer
to the .HYDROLOGY section for additional information regarding
river flooding potential. A High Surf Advisory also remains in
affect along the coast today with large breaking waves of 15 to
20 ft with a dominant period of 17 seconds. Large waves may run
further up area beaches.

Showers will linger into Sunday morning, mainly for areas King
County northwards and over the Cascades, before drier weather is
expected late Sunday into Monday morning. Another weather system
may move onshore into Oregon later Monday, resulting in
precipitation spreading northwards into portions of Washington.
Otherwise, temperatures will be a bit warmer today into the mid
50s and low 60s before temperatures in the low to mid 50 returns
Sunday.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...Precipitation from
the aforementioned system may linger into portions of Western
Washington Monday night, although some uncertainty remains into
the extent of precipitation Monday into early Tuesday. A brief
break between systems is likely on Tuesday, before another
stronger frontal system moves through Tuesday night into
Wednesday. This system also looks to bring the potential for
another round of breezy winds, particularly for the coast and
areas north of Snohomish County. Unsettled conditions are
expected to continue with another system Thursday into Friday
with troughing located offshore. Temperatures are expected to
remain near normal for much of next week. JD

&&

.AVIATION...Strong west southwesterly flow aloft weakening and
becoming westerly tonight into Sunday. Developing surface low
off Northern Washington Coast will move into Southern British
Columbia late this morning. Winds increasing over the interior this
morning then easing after 21z. Mostly MVFR ceilings this morning
with pockets of IFR ceilings mainly near the Olympics. Conditions
improving to VFR mid to late afternoon. Low level onshore flow
continuing overnight with ceilings returning to MVFR after 09z.


KSEA...MVFR cigs and visibility 3-5sm in rain at times through 21z.
Ceilings improving to VFR around 00z then lowering back down to MVFR
after 08z. South winds 4 to 8 knots increasing to 15 to 20 knots
with gusts 25 to 35 knots 15z-17z. Winds easing to 10 to 15 knots
after 21z and to 4 to 8 knots after 06z. Felton/McMillian

&&

.MARINE...A frontal system will move across the waters this
morning with increased southerly winds. Gale force wind gusts
expected for a period this morning for most waters, with Small Craft
Advisory winds for the northern Coastal Waters and western Strait of
Juan de Fuca. Winds will peak by early afternoon for most waters.
Onshore flow will increase behind the system this afternoon, with a
strong westerly push through the central and eastern portions of the
Strait of Juan de Fuca. Gales are expected for the Strait this
afternoon into early this evening.
Winds will then ease tonight into Sunday. Winds will transition more
east on Monday with another weak system expected late Monday into
Tuesday. A stronger frontal system will then move into the waters
late Tuesday into Wednesday for the return of Small Craft Advisory
winds and potential gales for the coast, as well as portions of the
interior waters.

Seas will build to 15 to 20 feet today, before subsiding to 10 to 15
feet on Sunday. Seas will further subside to near 10 feet on Monday
before building late Tuesday into Wednesday. JD

&&

.HYDROLOGY...Another 1.00 to 1.50 inches of rain forecast for
the Cascades and Olympics this morning. Rain rates decreasing
significantly after 18z with only another 0.25 inches in the
Olympics and 0.25 to 0.75 inches in the Cascades between
18z-00z. Snow levels remaining in the 8000-9000 foot range this
morning dropping quickly this afternoon to around 5000 feet in
the Olympics and North Cascades and 6000-7000 in the Central and
Southern Cascades. By 06z tonight snow levels all areas in the
4000 to 4500 foot range.

Rivers on the rise this morning but with the rainfall amounts
overnight a little less than expected most hydrographs running
below the forecast. With more rain to come will keep the flood
watch going but the chances for river flooding have diminished
overnight.

The two rivers of the most concern, the Skokomish and the
Skykomish near Gold Bar could still reach or get close to flood
stage later this morning into the afternoon hours.

Rivers flowing off the Central and Northern portion of the
Olympics are well within their banks and even with the
additional rainfall this morning will stay below action stage.

The rapid drop off in rain rates along the with the much cooler
air mass moving into the area will end the flood threat across
the area tonight.

There is still a chance this morning to get rainfall rates high
enough over the more sensitive burn scars for the potential for
flash flooding and or debris flows in those areas. Felton

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...Wind Advisory until 1 PM PDT this afternoon 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-
     Lowlands of Pierce and Southern King Counties-Lowlands of
     Western Skagit and Northwestern Snohomish Counties-
     Lowlands of Western Whatcom County-Northern Hood Canal-
     San Juan County-Shoreline / Lynnwood / South Everett Area-
     Southern Hood Canal.

     Flood Watch through late tonight for Cascades of Snohomish and
     Northern King Counties-Cascades of Southern King County-
     Cascades of Whatcom and Skagit Counties-City of Seattle-
     Downtown Everett / Marysville Area-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 the North Cascades-Foothills of the Western
     and Southern Olympic Peninsula-Lowlands of Pierce and
     Southern King Counties-Lowlands of Western Skagit and
     Northwestern Snohomish Counties-Lowlands of Western
     Whatcom County-Middle Chehalis River Valley-Olympia and
     Southern Puget Sound-Olympics-Shoreline / Lynnwood /
     South Everett Area-Southern Hood Canal-Willapa and Black
     Hills.

     Wind Advisory until noon PDT today for Foothills of the
     Western and Southern Olympic Peninsula-Grays Harbor
     County Coast-Lower Chehalis River Valley-Lowlands of
     Lewis and Southern Thurston Counties-Middle Chehalis
     River Valley-Northern Washington Coast-Olympia and
     Southern Puget Sound-Willapa and Black Hills.

     Wind Advisory until 7 PM PDT this evening for Island County-
     Port Townsend Area.

     High Surf Advisory until 5 PM PDT this afternoon for Grays
     Harbor County Coast-Northern Washington Coast.

PZ...Small Craft Advisory until 11 PM PDT this evening for Grays
     Harbor Bar.

     Small Craft Advisory until 4 AM PDT Sunday for Coastal Waters
     From Cape Flattery To James Island 10 To 60 Nm-Coastal
     Waters From Cape Flattery To James Island Out 10 Nm-West
     Entrance U.S. Waters Strait Of Juan De Fuca.

     Gale Warning until 8 PM PDT this evening for Central U.S.
     Waters Strait Of Juan De Fuca.

     Gale Warning until 8 PM PDT this evening for East Entrance
     U.S. Waters Strait Of Juan De Fuca.

     Gale Warning until 1 PM PDT this afternoon for Admiralty Inlet-
     Northern Inland Waters Including The San Juan Islands-
     Puget Sound and Hood Canal.

     Gale Warning until noon PDT today for 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 until 4 AM PDT Sunday for 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.

&&

$$