390
FXUS66 KSEW 300430
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
830 PM PST Sat Nov 29 2025

.SYNOPSIS...Cooler and drier weather is in store for the
majority of the week as high pressure settles into the area.
Some weak disturbances may drop into the region on the edge of
the ridge but it won`t amount to meaningful precipitation
accumulation. A stronger system may approach the region late
next week.

&&

.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...Mainly clear skies
this evening across Western Washington with high clouds along
the coast, and mid level clouds south of Olympia and in the
Strait of Juan de Fuca. Areas of fog will develop tonight from
Tacoma southwards to Chehalis, dense fog will be possible with
visibilities under 1/4 mile. Localized fog elsewhere with light
north winds. No major forecast updates this evening, previous
discussion below.

Some clearing is expected early tomorrow morning, with low
temperatures in the 30s where frost could materialize on
surfaces before sunrise. There will be a mix of clouds and sun
tomorrow, but it looks like more prolonged sun breaks could be
in store for Sunday. The next weak disturbance will bring light
rain to the area late Monday afternoon into the evening.
Rainfall amounts will be light with this system, where only a
couple hundredths to up to a tenth of an inch is expected. Snow
levels are expected to remain right at to slightly above pass
levels in the Cascades as well for light snow accumulation at
best.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...Precipitation will taper
off from north to south on Tuesday, with mostly cloudy skies
expected throughout the rest of the day. Highs through Wednesday
will remain in the upper 40s with cold overnight lows in the mid
30s for much of Puget Sound, and 20s in the Cascades and
adjacent foothills.

The pattern will become slightly more unsettled late in the week
as a slightly wetter system enters the region around a
flattening eastern Pacific ridge. There is still a significant
amount of uncertainty on the timing of the ridge beginning to
flatten out and what the late week system looks like in terms of
precipitation. The ensembles remain fairly persistent in the
ridge winning out where the deterministic models agree more on
the pattern change.

21

&&

.AVIATION...Northerly flow aloft will continue through Sunday
with an upper ridge positioned offshore. Mainly clear skies this
evening, with areas of mid and low clouds, mainly from Olympia
southwards and along the Strait of Juan de Fuca. Predominantly
VFR conditions tonight into Sunday for most areas. Fog will
develop around Tacoma and Olympia tonight (becoming more
widespread from 09z onwards) leading to LIFR cigs/vsbys for
KOLM and south Puget Sound. Localized fog will develop
elsewhere, mainly in river valleys. Otherwise, a few mid and
high clouds will be around into Sunday. Light E/NE surface
winds.

KSEA...Clear skies this evening. Fog is expected to remain
south of the terminal Sunday morning. Otherwise, FEW to SCT mid
clouds may develop Sunday morning. NE surface winds of 4 to 8
kts into Sunday. JD

&&

.MARINE...High pressure will continue to build over area waters
throughout the next week, with a series of systems crossing the
waters. While conditions remain benign today, a weak front will pass
over the Pacific Northwest later on Monday, bringing in elevated
northwest winds over the outer coastal waters nearing SCA criteria.
An additional weather system towards the end of next week will bring
in elevated westerly winds with potential for Small Craft westerlies
through the Strait of Juan de Fuca on Friday and next Saturday.

Seas around 5 to 7 feet this weekend will build to 9 to 12 feet on
Tuesday, easing back down to 5 to 7 feet by Wednesday. Seas are
expected to build to around 9 to 12 feet once again towards next
weekend.

15

&&

.HYDROLOGY...No river flooding is expected over the next 7 days.

&&

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

&&

$$