655
FXUS66 KSEW 111656
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
856 AM PST Tue Nov 11 2025

.SYNOPSIS...
Largely dry conditions are expected today as weak high pressure
builds into the area. The next system is offshore and is
expected to arrive in the area Wednesday afternoon into
Thursday. The pattern looks to remain active through the late
week into the weekend, with additional systems expected over the
weekend.

&&

.SHORT TERM /TODAY THROUGH THURSDAY/...
Satellite imagery and surface observations confirm localized
areas of dense fog, mostly spread across portions of the
Southwest Interior, the Chehalis valley up through Hoquiam,
through the Snohomish/Snoqualmie river valley, as well as some
of the valleys of the Cascades and eastern Olympics. This
should slowly burn off through the morning hours, giving way to
mostly clear skies this afternoon. High pressure aloft will keep
conditions dry today, with highs in the mid 50s.

Another system will arrive onshore early on Wednesday through
Thursday for a round of light rain and some mountain snow. Winds
will be lightly offshore on Wednesday, with breezy conditions at
times along the immediate coast. Snow levels will be higher,
6000-7000 feet on Wednesday, but look to decrease Thursday
afternoon to around 3800 feet, with mixed precipitation possible
along the Cascade Passes and higher areas of the foothills.

21/62

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
There is still some uncertainty late in the week about where the
core of the parent low pressure system will arrive onshore, but
the solutions seem to be converging somewhere along the Oregon
coast. Precipitation is forecast to continue into Thursday night
and Friday. None of these systems seem particularly impressive
as it relates to QPF, as storm total QPF from Wednesday morning
through Friday afternoon details around a half to three quarters
of an inch of rain throughout Puget Sound, and one to two inches
of rain in the Olympic and Cascade mountains. Snow levels come
down to around 3800 feet Thursday night into Friday morning for
some snow accumulation more likely at Stevens Pass than
Snoqualmie pass at this point.

An additional system over the weekend may be slightly wetter and
bring another round of snow accumulation in the mountains.

21

&&

.AVIATION...
High pressure will remain over the region today for dry weather.
The flow aloft is westerly and will become more southwesterly
late this afternoon as the ridge amplifies over the region and
an upper level trough digs southward across the northeastern
Pacific. Ample low level moisture brought fog to portions of
western WA this morning, along with IFR to MVFR conditions. Fog
will scatter by this afternoon for a return to VFR conditions.
Surface winds remain light and variable this morning and are
expected to increase towards 4-7 kt and shift to the N/NE by the
afternoon. Light rain will start to spread inland Wednesday
morning as a trough moves in from the west.

KSEA...VFR conditions this morning with light winds out of the
north. Northerly winds will increase to 4-7 kt by this
afternoon, before shifting to the southeast late tonight. Light
rain may move into the terminal by early Wednesday.

33/14

&&

.MARINE...
High pressure over the area today for generally light
winds. Next frontal system moving slowly through the waters
Wednesday night and Thursday with increasing southerly winds
over the waters. Strong onshore flow will follow Thursday
night. Meanwhile, seas will also build to around 10 to 13 feet.
Additional fronts will reach the area Friday and over the
weekend, keeping the pattern active. 33

&&

.HYDROLOGY...
High pressure will bring a brief break in precipitation today before
chances for heavier precipitation increase towards the end of
the week. While the second half of the week will be wetter, the
systems look to remain rather progressive across the region.
Rises will be possible on area rivers over the weekend, however,
at this time, no river flooding is expected.

14

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...None.

&&

$$