433
FXUS66 KSEW 100430
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
830 PM PST Sun Nov 9 2025

.SYNOPSIS...A frontal system will spread rain showers into
Monday. High pressure will rebound on Tuesday to provide brief
drying before a series of stronger and wetter systems move over
the Pacific Northwest through the remainder of the week.

&&

.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...Rain is moving
onshore over the Olympic Peninsula this evening as a weak
frontal system will slide across the area into Monday morning.
No major forecast updates this evening. Previous discussion
below:

High pressure remains in place across western Washington this
afternoon, in the warm sector of an approaching frontal system.
Temperatures will continue a warming trend today, peaking in the
60s across much of the lowlands. However, this will be the
warmest day of the period before a more active weather pattern
settles into the region.

A splitting frontal system will enter the Pacific Northwest
later today, spreading light showers inland over the Olympic
Peninsula later this afternoon and further inland throughout the
morning Monday. Showers may linger into the afternoon over
higher terrain and along the Pacific Coast, and high resolution
models continue to hint at post frontal convergence zone
showers continuing over the northern Puget Sound into Monday
evening. Precipitation amounts with this system will be light,
with roughly a tenth or two of rainfall across the interior
lowlands and up to an inch over higher terrain of the Olympics
and Cascades. Temperatures Monday will also return back into the
50s for most areas, where they will stay for the rest of the
week.

High pressure will rebound across western Washington into
Tuesday, allowing conditions to briefly dry out. With light
winds in place, patchy morning fog may form early Tuesday, but
confidence is low. Tuesday will be a seasonable fall day with
partly cloudy skies, some sun breaks, and high temperatures
near normal. Chances for any rain on Tuesday will be confined
to the Pacific Coast, with dry conditions inland.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...A more active weather
pattern will settle into western Washington Wednesday and beyond
as a series of troughs pass over the Pacific Northwest.
Forecast models show good agreement over the general synoptic
pattern, but continue to show some disagreement over the track
of the low pressure system entering the region towards the
latter half of the week. While some ensembles show the trough
moving inland over Washington and Oregon oN Thursday and Friday,
other ensembles show the low stalling southward along the
California Coast before pushing inland over the weekend. While
precipitation amounts remain uncertain at this time, confidence
is high that western Washington will see continued wet and
cloudy conditions Wednesday through the weekend. Near normal
temperatures in the low 50s across the lowlands are expected
throughout the long term.

15

&&

.AVIATION...A transition from exiting upper level ridge to
entering shortwaves on the back side of this feature will
gradually transition flow aloft from southwesterly overnight to
more zonal by Monday morning. Surface winds largely southerly
with variances to the southeast or southwest depending on
location. Speeds generally 4-8 kts although PAE is seeing speeds
up to around 10 kts this evening.

Widespread VFR conditions in place over W WA this evening although
some isolated spots of MVFR to IFR are possible along the coast. As
an approaching weakening shortwave approaches the area overnight,
most terminals should see cigs lower down to MVFR to IFR by 10Z
along with showers. While the lower cigs are expected to linger for
much of the TAF period, perhaps meeting with some improvement to VFR
in the mid to late afternoon, showers will be short lived as the
system falls apart on its eastward journey. A stray shower here and
there cannot be ruled out for the latter half of the TAF period,
however confidence is simply not there to warrant any inclusion of
such wording at this time.

KSEA...VFR conditions persisting this evening and into tonight
before cigs lower down into MVFR range around 10Z early Monday.
Models remain in agreement that any improvement in cigs to VFR will
likely hold off until the late afternoon...perhaps as late as around
sunset. Winds will remain largely south to southwest and speeds
remaining in the aforementioned 4-8 kt range. While still hinting at
PSCZ development early Monday evening, this feature is expected to
remain north of the terminal. A brief period of NE winds remains
possible, but again, confidence is not there to warrant inclusion of
this prospect in the TAF at this time.

18

&&

.MARINE...A weakening shortwave system will pass though the
waters tonight. High pressure will rebuild in its wake Monday
through Tuesday, before a more organized system moves through
Wednesday and Thursday. A small craft advisory remains in effect
through 12Z Monday for retreating gusty winds along the outer
coastal waters through late tonight over 20 kt (as well as 10-12
ft seas). A push down the Strait of Juan de Fuca Monday
night/Tuesday may bring breezy winds over 20 kt. The frontal
system Wednesday/Thursday may also bring wind gusts over 20 kt
to the coastal waters.

Seas Monday will decrease to 6 to 8 ft, and increase back to 9
to 12 ft Wednesday through Friday.

HPR/18

&&

.HYDROLOGY...A frontal system will bring light rainfall to
western Washington later tonight into Monday morning, with the
heaviest amounts up to an inch focused over the northwestern
Olympic Peninsula and North Cascades. High pressure will provide
a lull in rain before chances for heavier precipitation
increase towards the end of the week. No flooding is expected
over the next 7 days.

15

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Small Craft Advisory until 4 AM PST Monday 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.

&&

$$