Brier Weather Station
Latitude N 47° 46' 49" Longitude W 122° 16' 48" Elevation 341 ft
778
FXUS66 KSEW 271738
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
938 AM PST Thu Nov 27 2025
.SYNOPSIS...
A frontal system passing through western Washington will result in
steady rainfall throughout the Thanksgiving holiday before tapering
off overnight tonight. The weather pattern will trend drier and
eventually cooler Friday into early next week.
&&
.SHORT TERM /TODAY THROUGH SATURDAY/...
Latest radar imagery taking the shape of an upside-down L this
morning as precip associated with the warm front continues to lift
into the northern third of the CWA while precip associated with the
cold front moves eastward through the western half of the area.
While the pattern and rate of movement could hint at things starting
to taper off earlier than forecast, upper level support from the
main trough...expected to move through in the afternoon and evening
hours...will likely keep rain in the forecast for the bulk of the
day.
In fact, models are a little more sluggish in ejecting this upper
level low, so while PoPs are expected to gradually taper off
overnight, sufficient moisture may be present into Friday morning to
keep at least a chance of showers in place for the eastern half of
the area. From here, models remain consistent with bringing a pretty
healthy upper level ridge onto the coast Friday, resulting in
the bulk of the day being dry. Solution posed by the
deterministic ECMWF, with a shortwave impulse making its way
south along the leading edge of the ridge, bringing some rain
back to the area Saturday seems to have caught on with both the
deterministic GFS and a majority of ensemble members. That said,
no solution is terribly impressed with the amount of moisture
with this feature, bringing PoPs to low-end Chance /30 pct/ at
best and any rainfall generally well lower than 0.10 of an inch.
Temps continue to sound like a broken record with daily high temps
each day of the short term generally in the upper 40s to lower 50s.
Overnight lows however will see a cooling trend, starting off in the
lower to mid 40s tonight, dropping a few degrees Friday night to the
upper 30s to lower 40s before widespread temps in the 30s set up
shop for Saturday night.
18
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
The aforementioned impulse wastes no time getting out of the area by
Saturday night allowing ridging to once again hold court over the
eastern Pacific. This will at the very least keep the remainder of
the weekend dry. The ridge will start to break down at the start of
next week, however how quickly this occurs is a point of contention
between the two deterministic models: GFS keeping Monday mostly dry
while ECMWF has moisture entering the area as early as Monday
afternoon. Ensembles do not rule out the latter, but at this time
seem to be siding with the former. Current NBM is siding with the
majority on this one, so will leave this as is for the forecast.
Very strong high pressure remains over the eastern Pacific
throughout this and once again asserts itself, returning dry
conditions to the area by midweek.
Daytime highs continue the trend established in the short term,
generally in the upper 40s to lower 50s. With the flip-flopping
activity being just enough to bring clouds into the area from time
to time, overnight lows will nudge upward, mainly in the upper 30s
to low 40s, however the weak system expected for Tuesday will impact
Monday`s overnight lows, keeping them in the lower 40s.
18
&&
.AVIATION...Southeast surface flow will persist for most terminals
as the low pressure system nears the coast. Expect a transition to
ENE flow this afternoon, with gusty conditions along the immediate
coast and Chehalis Valley to 35 mph. Periods of rain through the
afternoon before more widespread rain arrives late this afternoon
into the overnight hours. Expect MVFR to IFR cigs in the heaviest
rain showers throughout the day, with visibility reductions as well.
Conditions will gradually improve early Friday morning with some
sunshine possible by the afternoon.
KSEA...Rain showers today with VFR cigs presently. ESE flow will
become ENE early this afternoon at 7 to 10 kts. Cigs are expected to
drop into MVFR as the rain moves over the terminal, becoming
predominantly MVFR into this afternoon and evening when the more
widespread rainfall arrives. Rain will taper after 10Z.
21
&&
.MARINE...A strong low pressure system will track near the
coastal waters and onshore between Grays Harbor and the mouth of
the Columbia River tonight before shifting inland and weakening. With
the tracking of the low, expect backing winds over the waters
from S/SE to N. While widespread gales are not expected,
occasional gusts to 35 kt will likely develop ahead of and south
of the low track. Updated the current advisory to break out the
coastal waters into the three segments to better capture these
differences. Seas will also build to around 11 to 15 ft. through
the day today. In addition, expect strong east winds through
the west and central Strait of Juan de Fuca. Wind and seas will
ease early Friday. High pressure then rebuilds this weekend and
into the start of next week, with the development of offshore
flow over the waters. 33/12
&&
.HYDROLOGY...
A passing frontal system will keep rain over the area for much of
the day today and into tonight. Snow levels will remain above
4000 feet today into the evening, leaving the majority of the
precipitation falling as rain. With expected rainfall amounts
holding steady and topping out mostly in the 2 to 2.5 inch range
with this system, confidence is increasing that we will not see
any river flooding impacts. After tonight, there is no additional
hydrologically significant precipitation expected through the
next seven days.
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Small Craft Advisory until 4 AM PST Friday for Central U.S.
Waters Strait Of Juan De Fuca-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