Brier Weather Station
Latitude N 47° 46' 49" Longitude W 122° 16' 48" Elevation 341 ft
367
FXUS66 KSEW 100940
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
240 AM PDT Sat Oct 10 2026
.SYNOPSIS...
Cool upper level low moving over the area this morning will
slowly move southeast into Eastern Oregon by Sunday morning.
Weak convergence over the Puget Sound ending this morning. Dry
northeasterly flow aloft tonight through Monday with high
pressure nosing into British Columbia. Ridge moves over Western
Washington Tuesday and weakens with a weather system moving by
to the north Tuesday night into Wednesday. Upper level ridge
building over Western Washington from the south Wednesday night
through Friday. Low level flow turning offshore producing a
couple of warm days the latter part of next week.
&&
.SHORT TERM /TODAY THROUGH MONDAY/...
Mostly cloudy skies over most of the area early this morning.
Some clearing along the coast and over the Southern Puget Sound
with a convergence zone to the north. Doppler radar indicating
scattered showers Skagit county to King county. A little cool
with temperatures at 2 AM/09Z in the lower 40s to lower 50s.
Cool upper level low moving over the area today. Weak
convergence producing the shower activity will dissipate this
morning. Low not strong enough to create any shower activity
this afternoon. Main result of the low overhead will be the cool
daytime temperatures with highs in the mid and upper 50s.
Seattle high Friday was 58 degrees, coolest high since May 15th
( 51 degrees ). Going for 57 degrees in Seattle today.
Upper level ridge nosing into British Columbia combining with
the upper level low drifting southeast producing dry
northeasterly flow aloft tonight and Sunday. Skies clearing
later this afternoon into tonight. With the clearing skies lows
dropping into the mid 30s to mid 40s. The frost advisory from
midnight to 8 am Sunday for portions of King, Pierce, Lewis and
Thurston counties remains in effect. Highs warming back to near
normal, upper 50s to mid 60s.
Upper level low sinking south Sunday night and Monday. Upper
level ridge remaining over Southern British Columbia with a
continuation of the dry northeasterly flow aloft. Low
temperatures even cooler Sunday night/Monday morning with most
places in the 30s. The last time Olympia had a low of freezing
or below was May 17th ( 32 degrees ). Another frost advisory
will be issued covering a larger area, most areas south of
Seattle plus the Hood Canal and North Coast for Monday morning.
Highs Monday again in the upper 50s to mid 60s. Felton
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
Upper level ridge axis moving south over Western Washington
Monday night into Tuesday. Weak atmospheric river settling up
Tuesday night into Wednesday aimed at Vancouver Island. A few of
the ensemble solutions have Western Washington on the southern
edge of this feature. Enough solutions to have a chance of rain
in the forecast Tuesday night and Wednesday. Lows in the mid
30s to lower 40s Tuesday and in the 40s Wednesday. Highs both
days in the upper 50s to mid 60s.
Upper level ridge building in from the south Wednesday night
into Thursday. 500 mb heights rising to the lower to mid 580
dms. Low level flow turning offshore as a front stalls well off
the coast. Right now it looks like a couple of warm days for
Western Washington with the warmer locations getting into the
lower 70s. Nowhere near records but still at least 5 degrees
above normal. Lows in the 40s. Felton
&&
.AVIATION...
Northwest flow aloft will become northeasterly late today as an
upper level low sinks southward over the Pacific Northwest. A
mix of MVFR and VFR ceilings in scattered showers this morning
will become VFR most areas this afternoon with shower activity
diminishing as the upper low shifts southeastward away from
Western Washington. Areas of LIFR fog are likely to form in
outlying valleys and across the Southwest Interior on Sunday
morning.
KSEA...Areas of MVFR ceilings in showers rotating around the upper
low will remain in the area into midday before diminishing with
ceilings lifting thereafter. Surface winds S/SE 6 to 9 knots will
veer to northerly after around 18Z this morning.
27
&&
.MARINE...
A weak surface low over the coastal waters this morning will shift
southward today. High pressure building over the interior of British
Columbia will lead to increasing northerly or offshore flow tonight
into Sunday. Winds will be briefly enhanced in the Northern Inland
Waters near the San Juans and off the coast in the central and
southern coastal waters zones, with potential for wind gusts to
approach Small Craft criteria tonight into early Sunday morning.
Winds ease early next week as high pressure over interior British
Columbia weakens and broad surface ridging remains centered well
offshore. Another frontal system will reach the waters Tuesday
night into Wednesday.
Coastal seas of 10 to 12 feet will subside later today and are then
expected to remain under 10 feet well into the upcoming week.
27
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...Frost Advisory from midnight tonight to 8 AM PDT Sunday for
Foothills and Valleys of Pierce and Southern King
Counties-Foothills and Valleys of Thurston and Lewis
Counties-Middle Chehalis River Valley.
Frost Advisory from midnight Sunday night to 8 AM PDT Monday
for Eastern Kitsap County-Foothills and Valleys of Pierce
and Southern King Counties-Foothills and Valleys of
Thurston and Lewis Counties-Foothills of the Western and
Southern Olympic Peninsula-Lake Crescent Area Including
US 101-Lowlands of Lewis and Southern Thurston Counties-
Lowlands of Pierce and Southern King Counties-Middle
Chehalis River Valley-Northern Hood Canal-Northern
Washington Coast-Olympia and Southern Puget Sound-
Southern Hood Canal-Willapa and Black Hills.
PZ...Small Craft Advisory until 5 AM PDT early this morning for
Grays Harbor Bar.
Small Craft Advisory until 8 AM PDT this morning for Coastal
Waters From Cape Flattery To James Island Out 10 Nm-
Coastal Waters From James Island To Point Grenville Out
10 Nm-Coastal Waters From Point Grenville To Cape
Shoalwater Out 10 Nm.
Small Craft Advisory until 2 PM PDT this afternoon for Coastal
Waters From Cape Flattery To James Island 10 To 60 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.
&&
$$
NWS SEW Office Area Forecast Discussion