Brier Weather Station
Latitude N 47° 46' 49" Longitude W 122° 16' 48" Elevation 341 ft
616
FXUS66 KSEW 211717
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
917 AM PST Fri Nov 21 2025
.SYNOPSIS...
High pressure will maintain drier conditions for much of the
region today before the next system brings in widespread
lowland rain, mountain snow, and breezy winds on Sunday. Cooler
and unsettled weather will continue into early next week, with
potential for additional systems to bring moderate to heavy rain
and mountain snow next week.
&&
.SHORT TERM /TODAY THROUGH SUNDAY/...
Weak ridging will continue to build inland today as isolated
showers continue near the Canadian border. Areas of fog have
already begun to develop early this morning, and light winds and
some clearing will continue to promote patchy fog this morning,
especially for areas south and west of the Puget Sound. A
frontal system will stall over British Columbia into the start
of the weekend, resulting in rain at times across the northern
Olympic Peninsula and northern interior, while conditions
generally south of Everett will remain dry and cloudy. As the
upper ridge flattens on Saturday, onshore flow will increase,
with breezy winds reaching 20 to 35 mph along the northern coast
and Whidbey Island northward. Temperatures will stay fairly
steady today in the low 50s across the lowlands, warming a few
degrees into Saturday.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
The frontal system stalled over British Columbia will swing
southward across western Washington late Saturday night into
Sunday, bringing widespread precipitation and breezy winds to
the region into Monday. Widespread precipitation will spread
into the region by early Sunday, with snow levels initially
around 5500-6000 ft lowering to 2000-2500 ft by Sunday evening.
The lowlands are on track to see generally up to a half inch of
rain through Monday morning, with 4 to 6 inches of snow
accumulation through most mountain passes. Forecast models
continue to show a post frontal convergence zone developing into
Monday, which will generate locally higher snowfall amounts
over the central Cascades.
A weak shortwave is on track to maintain showers mainly over
higher terrain on Monday, with light additional accumulations.
Weak ridging is favored to briefly dry out conditions on Tuesday
ahead of a potentially more active weather system mid-week.
Preliminary forecasts show significant incoming moisture to the
Pacific Northwest, with rainfall totals of up to an inch across
the lowlands and up to a foot or more of snow generally above
3000 ft. However, the amount of incoming precipitation will be
highly dependent on the track of the weather system which
remains fairly uncertain at this time. This storm system may
cause travel impacts towards the end of next week, particularly
through the Cascade Passes, which will continue to be closely
monitored as the Thanksgiving holiday approaches.
15
&&
.AVIATION...Mostly VFR this morning with mid/high clouds over
the region due to a flat ridge overhead. The flow aloft is
westerly. A passing front to the north will produce showers in
the northern terminals this afternoon/evening, and the coast
through Saturday. Outside of the isolated fog/mist this morning,
clouds will fill in with the front this afternoon, with VFR
decks gradually lowering to MVFR into Saturday morning (with IFR
from Kitsap down the Chehalis corridor). Winds remain out of
the S 5-10 kt later today into Saturday (could see a couple
terminal along coastal waters see a gust or two to 15-20 kt).
KSEA...Dry weather today with E winds veering to the south late
morning around 5 kt. Ceilings will fill in and gradually lower
from VFR down to MVFR Saturday morning (roughly after 10Z).
Winds pick up out of the S 5-10 kt (couple gusts to 15 kt are
possible).
33/HPR
&&
.MARINE...
An flat upper level ridge will pass through the waters
today, with a frontal system approaching from the northwest through
the weekend. Main concern in the short-term is seas - they remain at
11 to 15 ft in the coastal waters and Grays Harbor bar this morning.
They are expected to decrease down to 9 to 12 ft into the evening
(but remain high enough to keep the small craft advisories going for
the coastal waters, Grays Harbor bar and the west Strait of Juan de
Fuca). The wave height forecast keeps seas 9 to 12 ft through
Monday, before decreasing down to 6 to 8 ft through Wednesday and
increasing again to 9 to 12 ft Wednesday through the end of next
week as additional systems pass through. The next windy period for
the waters is with the Sunday/Monday system with a medium chance of
winds exceeding 20 kt in the coastal waters (high chance in the
Strait of Juan de Fuca), followed by another system
Tuesday/Wednesday.
Additionally, there are pockets of mist/fog in the waters close to
the Kitsap Peninsula this morning that may limit visibility at times
to mariners.
HPR
&&
.HYDROLOGY...
A weather system will move across western Washington late
Saturday into Monday for lowland rain and mountain snowfall. No
river flooding is expected during this period, but rivers will
rise. The potential exists for additional, heavier precipitation
during the middle of next week. However, uncertainty exists in
both the location and duration of precipitation. River levels
will continue to be monitored during this mid to late week
period.
JD
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Small Craft Advisory until 4 PM PST Saturday 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-Grays Harbor Bar-
West Entrance U.S. Waters Strait Of Juan De Fuca.
&&
$$
NWS SEW Office Area Forecast Discussion