624
FXUS66 KSEW 081002
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
302 AM PDT Wed Oct 8 2025

.SYNOPSIS...Cool and cloudy conditions will settle into western
Washington with periods of showers through the week as a low
deepens offshore. More widespread precipitation will enter the
region over the holiday weekend, with the first mountain snow of
the season.

&&

.SHORT TERM /TODAY THROUGH FRIDAY/...An upper level trough will
lower along the Pacific Coast from the Gulf of Alaska through the
remainder of the week, bringing in much cooler temperatures,
cloudy skies, and periods of light shower activity. As the low
strengthens and slowly creeps southward along the coast, wrap
around moisture will be advected northward into western Washington
to generate ample cloud cover and light shower activity. Today is
favored to be the driest day of the period, with isolated showers
confined to the Cascades. Rain showers will increase in coverage
on Thursday and once again on Friday, with generally light
rainfall totals. Temperatures through the rest of the week will
cool to more fall-like conditions, with highs in the upper 50s to
low 60s across western Washington.

.LONG TERM /SATURDAY THROUGH TUESDAY/...Ensembles continue to show
good agreement over a more active pattern emerging into the
weekend as the offshore low tracks inland and another trough drops
down from British Columbia. Temperatures over the weekend and into
early next week will cool even further, with most areas seeing
high temperatures below 60 degrees. As more widespread
precipitation enters the region, the cooler air will lower snow
levels to roughly 4000-5000 feet. This will bring a few inches of
accumulating snow to higher elevations, with mountain passes in
the North Cascades seeing the best shot at accumulating snow on
the roads. Surface temperatures may still be too warm to see much
impact through Stevens and Snoqualmie Passes, but any
recreationists heading to the higher elevations of the Cascades
and Olympics over the holiday weekend should prepare for snow and
much cooler temperatures.

Unsettled and cooler conditions are forecast to continue on into
early next week, with ensembles showing another low pressure
system moving into the Pacific Northwest. However, models show a
large spread of solutions beyond Monday.

15

&&

.AVIATION...Southerly flow aloft as an upper level low continues to
spin just offshore. A mix of VFR and MVFR this morning as stratus
continues to fill in through the Salish Sea interior lowlands from
Seattle/Bremerton and northward. MVFR cigs will likely continue for
these locations through the morning before lifting and breaking up
throughout the day. VFR conditions will continue through the rest of
today and tonight. Increasing mid level clouds tonight into early
Thursday morning should keep widespread fog/low cloud concerns
mostly at bay. Light winds winds this morning will become
south/southwesterly 4 to 8 kt during the day.

KSEA...MVFR cigs early this morning will persist through much of the
morning, lifting and breaking out after around 17-19Z. VFR conditions
prevail through the remainder of the period. Mid and high level
clouds will increase late tonight into early Thursday morning. Calm
winds this morning will become southwesterly 5-8 kt late this
morning through this evening. Winds become light north/northeasterly
4 kt or less after 03Z Thursday through the overnight period.

62

&&

.MARINE...A mostly dry cold front has traversed across western
Washington, keeping northwesterly winds going across the coastal
waters. Seas 7 to 12 will continue through today, with seas
remaining steep with a dominant period of 8 seconds. Winds will ease
below Small Craft Advisory level late this morning, with seas
following suit, lowering below 7 ft this evening. A low pressure
system will form over the offshore waters on Thursday. The system
will move onshore to the southwest Friday into Saturday but weaken
as it does so.

Winds will become offshore on Thursday and Friday as the low
pressure system remains over the waters. Seas remain around 5-7 ft.
As it moves inland, winds will return to being onshore and
strengthen. Additional headlines will likely be needed on Saturday
with high probabilities (60-80%) for gale force winds across the
coastal waters as well as the central Strait of Juan de Fuca. Seas
will also increase, building up to around 12-15 ft, with the highest
seas over the northern portions of the coastal waters.

Another system may develop Sunday night into Monday over the region,
bringing another round of breezy winds, but model discrepancies
increase at this time range.

62

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Small Craft Advisory until 5 AM PDT early this morning for
     Central U.S. Waters Strait Of Juan De Fuca.

     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 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.

&&

$$