Brier Weather Station
Latitude N 47° 46' 49" Longitude W 122° 16' 48" Elevation 341 ft
853
FXUS66 KSEW 242154
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
254 PM PDT Sat Oct 24 2026
.SYNOPSIS...An offshore storm system moving into area today
will very gradually shift south and east through Monday morning.
This will bring widespread rain and breezy conditions through
Sunday morning followed by showery unsettled weather into the
start of the week. The pattern looks to remain very seasonal for
the last week of the month - cooler with a series of systems
bringing periods of unsettled weather nearly every day.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...The offshore
system that has been sliding down the British Columbia coast,
has begun to move into the coastal waters of Washington, with
light warm frontal precipitation spreading into the north
Olympic Peninsula and north interior early this afternoon. This
is expected to lift north into British Columbia this evening as
the trailing cold front begins to move onshore. REFS guidance
showing the cold front slowly moving onshore overnight as the
parent system takes it`s time moving south and east.
Precipitation with the cold front will be heavier that the
lighter rain Saturday. While this ultimately is a fairly typical
October storm system, it is the first Fall-like system to move
into the area, and will definitely feel different as such.
Heavier precipitation amounts are expected along the coast and
Olympic Peninsula with 24 hour amounts through Sunday evening in
the neighborhood of 1-2 inches, and 0.50 to 1 inch along the
I-5 corridor eastward. In addition to the rainfall, increasing
south winds along the coast this evening will spread inland
ahead of and with the front, remaining breezy through Sunday.
Peak wind gusts of 20 to 35 mph are possible for many areas.
The parent upper level system is expected to continue its slow
south-southeast track through the day Sunday into Monday.
Ensembles showing more agreement in the track of the upper level
low than the surface low. The higher resolution REFS ensemble
hinting at a more northerly track with the ensemble mean showing
the surface low moving into Grays Harbor late Monday morning,
while many of the other higher resolution ensembles like the
HREF and UW ensemble systems show a much more southerly track.
In any case, with the upper level low over the area Sunday into
Monday morning, scattered, but widespread showers will
linger well into Monday before shifting east with the upper
level support late Monday afternoon.
High temperatures will trend near normal in the mid to upper
50s, while overnight lows will trend cooler than normal in the
in the low 30s to low 40s.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...The grand ensemble
remains generally consistent early in the week with the upper
level trough associated with the weekend system shifting into
the northern Intermountain area Tuesday morning. Ensembles all
hint at a trailing shortwave sliding down the British Columbia
coast, with variability in the strength and timing. The
consistent message is that the bulk of the relatively light
precipitation looks to be focused mainly south of western
Washington Tuesday. Ensembles very consistently showing a more
consolidated upper level low sliding down the BC coast Tuesday
night and into western Washington Wednesday. This looks scenario
very similar in many ways to this weekend`s system, with cooler
temperatures and widespread rain over much of the Pacific
Northwest. The pattern looks to remain unsettled Thursday into
Saturday with a broad positively tilted upper level trough along
the Western US. Some scenarios showing a more consolidate upper
level low over California. For the Pacific Northwest the
pattern looks to remain unsettled - but seasonal - through the
last few days of the month.
&&
.AVIATION...Southwest flow aloft increases into Sunday, becoming
more southerly by Sunday afternoon as an upper trough digs offshore.
Widespread VFR mid and high clouds this afternoon across western
Washington ahead of a frontal system. Cigs will lower into MVFR/IFR
along the coast and near BLI tonight as rain continues to slowly
spread southeastwards. Low-end VFR to high-end MVFR cigs expected
for most southern and central Puget Sound terminals by early Sunday.
Lower VFR cigs for the afternoon for interior, with continued MVFR
for portions of the Olympic Peninsula Sunday afternoon. Vsby
reductions possible in areas of steadier rain into Sunday, dropping
to 3 to 6SM, lowest along the coast. Increasing S/SE winds for the
coast, and E/NE winds for BLI into tonight, remaining light for KPAE
to KTCM into Sunday.
KSEA...VFR continues through tonight with mid and high clouds. Cigs
slowly lowering towards MVFR by Sunday AM. At this time, the
probability for MVFR cigs peaks between 13 to 18z Sunday as rain
arrives, with probabilities around 25 to 30%. Rain at times into
Sunday PM, with brief reductions to vsbys possible. VFR for Sunday
afternoon with continued OVC mid clouds. Light west winds this
afternoon, with a light E/NE component tonight into Sunday.
&&
.MARINE...A surface low offshore of Vancouver Island will continue
to slowly shift southwards along the offshore waters through this
weekend before weakening and moving onshore in the vicinity of NW
Oregon on Monday. East to southeast winds will increase into tonight
ahead of the approaching system. Small Craft Advisory southerly
winds continue for a longer duration over the Coastal Waters through
at least Sunday afternoon. Gale force wind gusts are also expected
at times for the northern outer Coastal Waters through this evening.
Southeast winds also increase for the eastern Strait of Juan de
Fuca, northern inland waters, and Admiralty Inlet early Sunday. The
SCA has been upgraded to a Gale Warning for the east Strait given
the higher confidence in gale force wind gusts, along with SCA winds
for northern inland waters and Admiralty Inlet. Otherwise, east
winds remain elevated for the eastern and western Strait of Juan de
Fuca into Sunday. Will need to monitor any additional upgrades to
gales, mainly for the far eastern segment of the central Strait.
Winds remain light for Puget Sound into Sunday. Winds subside Monday
into Tuesday with another system expected to move through the area
on Wednesday..AVIATION...
Westerly flow aloft will transition southwesterly and
increase into tonight as an upper trough digs southwards over the
Washington offshore waters. Increasing VFR mid and high clouds today
ahead of a frontal system with localized LIFR/IFR over HQM this
morning. Cigs may brief fluctuate into high end MVFR at KBLI
this afternoon. Cigs slowly lower over the Olympic Peninsula
into MVFR/IFR tonight with increasing rain. High end MVFR to low
end VFR cigs for Puget Sound terminals Sunday as the frontal
system moves across the interior. Vsbys reductions may occur in
steadier rainfall over the Olympic Peninsula terminals.
Increasing south winds along the coast later today, with light
winds for central and southern Puget Sound.
KSEA...VFR conditions through tonight with continued mid and
high clouds. Dry conditions into tonight, with rain potential
increasing around 12-15z Sunday. Cigs also lowering towards low-
end VFR at the onset of the rain Sunday AM. Southeast surface
winds becoming more SW this afternoon, mainly less than 5 kts.
Surface winds transition back to more E/NE this evening and
tonight, remaining light. JD
&&
.MARINE...
A surface low southwest of Haida Gwaii will shift
southward today into tonight and an associated occluded front
will clip the coastal waters on Sunday morning. Increasing
easterly or southeasterly gradients will lead to small craft
advisory winds across the coastal waters as well as the Strait
of Juan de Fuca. Seas will build to 10 to 12 feet over the
coastal waters late today into Sunday. The surface low is
expected to move onshore over northwest Oregon Sunday night into
Monday with winds easing and seas subsiding back below 10 feet.
Another frontal system will shift southward into area waters on
Wednesday.
27
&&
Seas will build to 8 to 12 feet tonight before subsiding below 10
feet by early Sunday night. Seas will then remain in the 4 to 7 foot
range for the majority of the week. JD
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Small Craft Advisory until 5 PM PDT Sunday for 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 Point Grenville To Cape Shoalwater 10
To 60 Nm-West Entrance U.S. Waters Strait Of Juan De Fuca.
Small Craft Advisory from 5 PM this afternoon to 5 PM PDT
Sunday for Central U.S. Waters Strait Of Juan De Fuca.
Small Craft Advisory from 8 PM this evening to 5 PM PDT Sunday
for East Entrance U.S. Waters Strait Of Juan De Fuca.
Small Craft Advisory until 5 PM PDT Sunday for Coastal Waters
From James Island To Point Grenville Out 10 Nm-Coastal
Waters From Point Grenville To Cape Shoalwater Out 10 Nm.
Gale Warning until 11 PM PDT this evening for Coastal Waters
From Cape Flattery To James Island 10 To 60 Nm.
Small Craft Advisory from 11 PM this evening to 5 PM PDT
Sunday for Coastal Waters From Cape Flattery To James
Island 10 To 60 Nm.
&&
$$
NWS SEW Office Area Forecast Discussion