613
FXUS66 KSEW 011636
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
936 AM PDT Thu Oct 1 2026

.SYNOPSIS...A weak system will bring precipitation chances
across northern portions of Western Washington. Warmer and drier
conditions Friday into the weekend with high pressure settling
over the region. Onshore flow returns next week for a return of
closer to normal temperatures but continued dry conditions into
next week.

&&

.SHORT TERM /TODAY THROUGH SATURDAY/...Mid and high clouds
continue across portions of Western Washington this morning. An
upper-level zonal pattern will remain over the region through
Friday afternoon. A weak system system moving northeast into
British Columbia will clip portions of northern Western
Washington and bring the chance for light showers for the North
Coast, Olympic Peninsula, and Whatcom County today into Friday.
Today`s high temperatures will be in the upper 50s to low 60s
along the coast and mid to upper 60s. Warmer and drier
conditions Friday into Saturday as surface high pressure builds
over the region. High temperatures will warm into the low 60s
along the coast and upper 60s to low 70s in the interior.
Additionally, a thermal trough will build along the coast on
Saturday, leading to surface winds to switch offshore. 29

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...Ensemble
guidance remains consistent with high pressure in place over the
region with a thermal trough remaining over the area. This will
bring light offshore flow to the region and maintain
temperatures above normal on Sunday. With the thermal trough
pushing eastward and a return to onshore flow, expect to see
temperatures trend a few degrees cooler for the start of next
week with increased morning clouds. Dry conditions are likely to
continue through at least the middle of next week.

&&

.AVIATION...VFR with high clouds today. BCFG has been observed
across a couple of inland terminals this morning but should
subside by 16-17z. While winds will be light tonight, high
clouds passing through should help limit fog development. A weak
weather system moving into British Columbia could bring light
rain showers near northernmost terminals (CLM & BLI) today. Calm
to light northerly surface winds this morning. Surface winds
will transition southerly late this evening.

KSEA...VFR conditions will prevail today with high clouds. Surface
winds northwesterly at 5-6 kt or less. Winds will shift southerly
late this evening around 07Z. 29

&&

.MARINE...High pressure returns to the waters this week. A
passing front to the north may clip the waters, but won`t do
much to increase any marine weather concerns. A building thermal
trough will bring northerly or offshore breezes over the
weekend. Seas become a little steeper over the coastal waters as
a result, but expect conditions to remain well short of
steepness criteria for an advisory. Otherwise, the breakdown of
the high pressure could bring a stronger westerly push late
Monday through Strait of Juan de Fuca, and represents the next
potential chance for advisory conditions.

&&

.FIRE WEATHER...Fire weather concerns remain minimal through
the next few days. Developing high pressure aloft this weekend
with a thermal trough building up the coastline will bring warm
temperatures and light offshore flow. This could result in
locations in the Cascades and adjacent valleys seeing minimum RH
values approach 30% on Sunday. This will be short lived, with
onshore flow returning early next week to boost humidity values
and cool temperatures.

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...None.

&&

$$