447
FXUS66 KSEW 172208
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
308 PM PDT Fri Oct 17 2025

.SYNOPSIS...A weak frontal system will move across the area
this morning. A stronger, wetter system will follow Saturday
afternoon into Sunday morning bringing breezy winds, lowland
rain, and mountain snow. Showers will continue through Sunday with
a a chance of thunderstorms. A brief lull in the action Monday
before more weather systems take aim at Western Washington Tuesday
through the end of next week, keeping the pattern active.

&&

.SHORT TERM /TODAY THROUGH SUNDAY/...Light showers will continue
to taper throughout the evening as some mid to high level cloud
cover continues to stay around. Low temperatures tonight will be
in the low to mid 40s across much of the area, maybe a little bit
cooler for areas along the water.

Attention turns to Saturday as a stronger and wetter frontal
system will cross over western Washington. Rain will start
spreading along the coast midday, with widespread rain reaching
the interior locations by Saturday evening into the overnight
hours. Winds will also become breezy later Saturday evening
heading into Sunday morning with gusts potentially up to 20 to 30
mph at times. Showers will continue over the area on Sunday, with
the bulk of precipitation with this system happening over the
Olympics and Cascades. Snow levels look to fall back down towards
4500 to 5000 feet in the wake of the front on Sunday, bringing
some snow to the higher elevations of the mountains - especially
the North Cascades, where a Winter Weather Advisory will be in
effect. Most of the heaviest accumulations will be above 4500
feet, affecting mostly Rainy Pass. Total QPF amounts will
generally be 1-2 inches across the mountains with locally higher
amounts, especially with the changing snow levels. Areas across
the interior will see totals around a half an inch to an inch of
rain. Though this event will be a good primer for area rivers, the
antecedent dry conditions lend little concern for any flooding at
this time.

Conditions will generally dry late Sunday evening along with winds
easing. High temperatures will generally be in the mid to upper
50s across much of the interior.

.LONG TERM /MONDAY THROUGH THURSDAY/...Ensembles in good agreement
with shower activity drying up on Monday as a weak upper level
ridge moves over the area. Conditions look to remain dry into
Tuesday with some light showers potentially over the Cascades.
Another system looks to arrive Wednesday into Thursday with a lot
of variability regarding timing and strength of said system - but
looks like another round of moderate widespread rain and breezy
conditions is likely for end of the week.

Mazurkiewicz

&&

.AVIATION...VFR cigs have returned across western Washington this
afternoon, with generally northerly to easterly flow. Wind
directions are not very uniform this afternoon, with areas along the
coast and southwest interior showing westerly winds, with
southeasterly winds through southern Puget Sound and northeasterly
from around KPAE north. Winds are going to become light area wide
this afternoon and evening, becoming variable. A return to MVFR to
IFR cigs are likely overnight for areas in southern Puget Sound and
the Chehalis Valley. With more rain coming in tomorrow afternoon and
evening, expect reductions in cigs and visbys that will carry into
Sunday.

KSEA...VFR with southeasterly winds at the terminal this afternoon.
This is a change from the previous expectations of more northerly
winds and has been reflected in the 21Z TAF update. Model guidance
is now suggestive of a more easterly wind throughout the rest of
this afternoon and evening, lightening up and becoming southeasterly
again to variable overnight. Southerly winds return tomorrow morning
as the next weather system moves into the area and brings about more
rain. As it arrives, expect cig and visby reductions to MVFR and
around 4SM at times.

21

&&

.MARINE...Weak high pressure behind a frontal passage will continue
to build over area waters through Saturday morning. Post-frontal
winds will continue through the Central Strait of Juan de Fuca
through this evening, with a Small Craft Advisory remaining in
effect. A much stronger frontal system will move over area waters
Saturday into Sunday, with numerous Small Craft Advisories across
the outer and inner waters over the weekend. A series of additional
frontal systems will cross the region through next week.

Seas currently at 9 to 11 feet over the outer waters will reach the
inner waters tonight. Seas will remain elevated through the weekend,
building as high as 20 feet across the outermost outer waters and 15
feet along the coastal waters on Sunday. Seas may be steep at times,
especially Saturday night into Sunday. Seas are expected to fall
below 10 feet briefly on Monday before building back to 10 to 16
feet through the remainder of the week.

15


&&

.HYDROLOGY...A frontal system will bring widespread rainfall to the
region over the weekend, with up to an inch of rain across the
lowlands and 1 to 3 inches over the mountains. While this influx of
moisture is not expected to cause any river flooding, it could cause
rapid rises on sensitive streams and creeks, potential impacts to
burn scars, and localized urban flooding. Conditions will dry out on
Monday and Tuesday, but additional storm systems could potentially
bring significant rainfall to western Washington towards the end of
next week.

15

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...Winter Weather Advisory from 11 PM Saturday to 11 PM PDT Sunday
     for Cascades of Whatcom and Skagit Counties.

PZ...Small Craft Advisory from 2 AM Saturday to 6 PM PDT Sunday for
     Grays Harbor Bar.

     Small Craft Advisory from 6 PM Saturday to 6 PM PDT Sunday 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-West Entrance U.S. Waters
     Strait Of Juan De Fuca.

     Small Craft Advisory until 5 PM PDT this afternoon for Central
     U.S. Waters Strait Of Juan De Fuca.

     Small Craft Advisory from 6 PM Saturday to 6 AM PDT Sunday for
     Admiralty Inlet-Puget Sound and Hood Canal.

     Small Craft Advisory from 6 PM this evening to 6 PM PDT Sunday
     for Coastal Waters From Cape Flattery To James Island Out
     10 Nm-Coastal Waters From James Island To Point Grenville
     Out 10 Nm-Coastal Waters From Point Grenville To Cape
     Shoalwater Out 10 Nm.

     Small Craft Advisory until 6 PM PDT Sunday for Coastal Waters
     From Cape Flattery To James Island 10 To 60 Nm-Coastal
     Waters From James Island To Point Grenville 10 To 60 Nm-
     Coastal Waters From Point Grenville To Cape Shoalwater 10
     To 60 Nm.

&&

$$