310
FXUS66 KSEW 101649
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
949 AM PDT Fri Oct 10 2025

.UPDATE...No updates to the overall forecast. Cool and unsettled
weather will settle over the region through early next week.
Please see the aviation section below for updates to that
forecast.

&&

.SYNOPSIS...An upper low offshore will maintain cool and
unsettled conditions across western Washington into the weekend.
The next disturbance moves southward from British Columbia by
the end of the weekend, bringing the first noteworthy high
elevation snow of the season. Drier conditions will return
toward the middle of next week as high pressure rebuilds over
the region.

&&

.SHORT TERM /TODAY THROUGH SUNDAY/...Continued showers across
portions of the region early this morning, with the main band of
precipitation still holding near 126W off the northern but
extending southeast near the mouth of the Columbia River. Expect
this area of steadier rain to increase through the day as this
frontal band moves through the area. Could see a few isolated
thunderstorms over the waters and near the coast as the main
upper trough slides eastward later today with the lapse rates a
little steeper in conjunction with the colder air aloft closer
to the center of the disturbance. Temperatures will remain near
normal Friday, trending cooler with highs over the lowlands in
the mid to upper 50s Saturday. The next disturbance deepens and
moves into the region late in the weekend as it pushes south.
This will bring another round of widespread precipitation to the
region as well as usher cooler air across Western Washington.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...Behind the
aforementioned upper trough, expect to see another round of
moisture move across the area. The surge of colder air arriving
behind this system will bring much lower snow levels, down to
around 3000 feet in the northern Cascades to 4000 ft in the
southern Cascades by Monday morning. This will open the door the
first notable high elevation snowfall for the higher Cascade
elevations. While roadside accumulations at Rainy Pass (most
likely 2-4") and Stevens Pass (1-3") are possible, the amounts
will be higher in the higher elevations. Even at Snoqualmie
Pass, where accumulations are not expected, there`s still the
likelihood of periods of snow mixed in with rain. Those that
plan to head to the higher mountain elevations this weekend
should be prepared to encounter snow and cold conditions and
closely monitor the weather forecast in the next few days.

Ensemble guidance continues to favor the upper low tracking
south into California. This begins to push the precipitation
chances away from the region, bringing a drier trend and
decreasing cloud cover. This will bring some elevated concern
for morning frost Monday and Tuesday as clearing skies and light
winds yield efficient cooling and temperatures may reach the mid
to upper 30s for the sheltered interior locations away from the
water. After a few dry days, guidance favors a return of a more
active pattern, and associated precipitation chances, late in
the week.

&&

.AVIATION...Southeasterly flow aloft with an upper level low
off the Oregon coast. A mixed bag of ceilings this morning with some
VFR and MVFR across the region. Bands of showers will move across
the area later this morning through much of the daylight hours,
which should help to slowly fill in and lower ceilings to MVFR for
much of the day. Ceilings may be able to lift and break enough for
some low end VFR this evening, but expecting MVFR conditions to
persist through tonight and may lower even further to IFR by early
Saturday morning. Light winds will become southerly 5 to 10 kt later
this morning and persist through the rest of the TAF period.

KSEA...VFR/MVFR ceilings this morning. Bands of showers will move
across the terminal throughout the day which should keep MVFR
cigs through the TAF period. Ceilings may be able to lift and
break just enough for VFR conditions after around 22z Fri through
00Z Sat but should return to MVFR by 06Z Sat. Ceilings look to
continue to slowly lower into early Saturday morning and could be
close to IFR. Southerly winds 5 to 10 kt through the period.

62/Mazurkiewicz

&&

.MARINE...The low pressure system offshore will begin to move
inland today into early Saturday and weaken as it does so. High
pressure will quickly build in behind the system early Saturday.
Winds increase over the coastal waters Saturday morning and
last through early Sunday morning. Sustained winds will reach
high-end SCA criteria, with 50-90% chance for gale force gusts.
With this, a Gale Watch has been issued for the outer coastal
waters zones north of Point Grenville for this time period.
Winds through most of the interior waters should remain below
thresholds, through there is a 30-50% chance that winds through
portions of the Central Strait of Juan de Fuca reach above 21
kt. Winds ease on Sunday but begin to turn offshore as another
low pressure system develops along the coast of Vancouver
Island. As this system develops and begins to move southwards
Sunday night, winds will begin to increase through the Strait of
Juan de Fuca and the Northern Inland Waters. Winds look to
reach SCA criteria in these locations, with a 40-50% chance for
winds to reach gale force through portions of the central
Strait. Winds will ease Monday night into Tuesday morning as the
low moves southward along the Pacific coast. Winds look to
remain lighter from Tuesday and beyond as broad, weak high
pressure builds across the region.

Seas 3 to 5 ft tonight will linger into Friday then build Saturday
to 12 to 16 ft. Seas then look to ease Sunday, dropping below 10 ft
Sunday night, then becoming 6 to 8 ft for the first part of next
week.

62

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Gale Watch from Saturday morning through Sunday 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.

&&

$$