801
FXUS66 KSEW 250001
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
401 PM PST Mon Nov 24 2025

.SYNOPSIS...
Lingering showers mainly over the higher terrain will taper off
overnight. Precipitation will return to the area Tuesday, with
lowland rain, and mountain snow through Tuesday becoming mostly
rain through the day Wednesday. Unsettled weather is expected
through the holiday and into the weekend with periods of
precipitation and cooler conditions.

&&

.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
Lingering showers, mainly over the higher terrain will taper off
overnight, aided by a brief period of short wave ridging. A
stronger system will approach the Pacific Northwest Tuesday,
with widespread precipitation beginning to move onshore during
the morning. Snow levels will begin the day Tuesday 1500 to
2000 feet with snow accumulations as precipitation moves into
the area - particularly through the Cascade Passes. 8 to 10
inches is possible at all of the Cascade passes before snow
levels begin to rise Tuesday evening. In addition there is a
chance of a wintery mix at Snoqualmie Pass during the evening
hours as warmer air rides over cold easterly flow in the pass,
with a 30% chance of freezing rain for a period before the pass
transitions over to rain later Tuesday night.

Snow levels should rise to well above 5000 feet by midday
Wednesday with precipitation transitioning to rain for all but
the higher ridges and volcanos. Ensembles continue to highlight
a trailing system setting up a second surge of moisture with a
warm front later Wednesday afternoon into to the evening. Snow
levels will remain generally above 6000 feet, with the heaviest
precipitation - mainly rain over the coast and Olympics
Wednesday night.


&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
The trailing system is expected to move into the coastal waters.
Ensemble guidance at this point in good agreement at the cold
front moving onshore through the day Thursday with the
associated surface low moving onshore somewhere along the
Washington coast to the west coast of Vancouver Island in
British Columbia. The approaching surface low and its landfall
will result in some breezy to gusty winds - most likely along
the coast. The nature and location of the strongest winds will
depend ultimately on the track of the low, and this will be one
of the details going into the Holiday that will be monitored.
Temperatures should cool somewhat behind the cold front into
Friday, with snow levels dipping back down to around 3500 feet.

Ensemble mean forecast suggest some degree an upper level ridge
settling in over the Eastern Pacific Saturday into Sunday -
setting up the Pacific Northwest for a cool north-to northwest
flow aloft and some possibility of weak system brushing the area
late in the weekend.

&&

.AVIATION...
Post-frontal showers continue this afternoon and expected to subside
throughout the evening hours. A stronger frontal system will impact
the terminals on Tuesday, bringing steady rain. Rain looks to arrive
around 11Z/12Z for the coast and Strait; as for interior terminals
the rain will arrive around 14Z/15Z. Ceilings are expected to drop
after 14Z-16Z to MVFR. Latest guidance suggests IFR conditions are
possible after 19Z, with a 20-40%. Greatest chances of IFR are for
PWT and OLM. In addition, expect reduced visibility to 1-3 SM during
the heavier bands of rain.

KSEA...Steady rain expected at the terminal as early as 15Z on
Tuesday. Ceilings will drop to MVFR after 15Z-16Z. There is a small
chance (20-30%) of IFR conditions between 19Z-03Z. Southwesterly
flow this afternoon will become southeasterly late tonight.

29

&&

.MARINE...
A frontal system is expected to pass over area waters, bringing
increased winds to area waters starting Tuesday morning. Winds for
the coastal waters, east entrance of the Strait, and Admiralty Inlet
are likely to meet small craft thresholds for which a Small Craft
Advisory has been issued. Low-end gale gusts possible at times for
the outer coastal waters Tuesday morning. Seas with this system will
build to 7-11 ft by Tuesday afternoon, with the highest waves for
the outer coastal waters.

A stronger system on Thursday will bring another round of elevated
winds and waves. Latest guidance highlights a 50-70% chance of gusts
exceeding 21 kt for the coastal waters and Strait of Juan de Fuca.
In addition, guidance suggests seas will build to 13-17 ft Thursday
evening.

29

&&

.HYDROLOGY...
A stronger weather system will move into Western Washington late
Tuesday, with continued precipitation at times through Thursday. The
storm total precipitation are higher today but there remains
uncertainty in the QPF among models.  Rivers will rise as a result
of the steadier precipitation, especially for rivers off the central
and southern Cascades, as well as the Olympics. Snow levels will
also rise to 5500 to 6500 feet by late Wednesday. At this time, the
Skokomish River in Mason County is the primary river being monitored
for river flooding by Thursday. The potential is there and as such a
Flood Potential Outlook for Mason County. Current rainfall and river
forecasts indicate a crest on the Skokomish right around flood
stage. This, as well as other rivers, will continue to be monitored.

18

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...Winter Weather Advisory from 10 AM Tuesday to 4 AM PST
     Wednesday for Cascades of Pierce and Lewis Counties-
     Cascades of Snohomish and Northern King Counties-Cascades
     of Southern King County.

PZ...Small Craft Advisory from 8 AM Tuesday to 1 AM PST Wednesday
     for East Entrance U.S. Waters Strait Of Juan De Fuca.

     Small Craft Advisory from 10 AM to 10 PM PST Tuesday for
     Admiralty Inlet.

     Small Craft Advisory from 4 AM Tuesday to 1 AM PST 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.

&&

$$