Brier Weather Station
Latitude N 47° 46' 49" Longitude W 122° 16' 48" Elevation 341 ft
375
FXUS66 KSEW 212124
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
224 PM PDT Wed Oct 21 2026
.SYNOPSIS...
Dry weather will largely continue for most in western Washington
through the end of the week. A weak front moving through
Thursday into Friday will have a slight chance of producing
isolated showers in the south sound. A more organized upper low
will dig south into the Pacific this weekend, chances of showers
resuming Saturday through the middle of next week. Snow levels
will drop to near 3,000 to 4,000 feet on Saturday, which may
lead to some mountain snow showers, along with more widespread
lows in the 30s on Saturday morning.
&&
.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
A split-flow pattern continues in the upper atmosphere with an
upper level low deep into California, and the jet stream still
north into Canada. Skies have cleared this afternoon with the
only clouds high over the Pacific and north interior. High
temperatures today will still warm into the mid and upper 60s
(with a couple 70s down south). Cloud coverage increases tonight
into Thursday with a weak cold front moving through in the
morning. No precipitation is expected when the front passes
through in the morning. However, there will be a 20 percent
chance of showers with a post-frontal convergence zone in the
afternoon for those in the south interior/south sound. Winds
will likely increase out of the northwest on the Pacific Coast
Thursday night, with gusts to 25 to 35 mph. Cloud coverage will
clear Friday afternoon, although high temperatures will be a
few degrees cooler (mid to upper 50s). Depending on how long the
clear skies are able to hold on Friday night into Saturday
morning, there may be instances of lows in the mid 30s for some
frost potential (especially down in the south interior).
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
The models/ensembles are still having some trouble coming to an
agreement as to how an upper level low/trough will develop and
evolve going into this weekend into next week. Most operational
runs have the low dropping south into the Pacific (just off the
coast), though it becomes more split as to if the low will
remain in place, or move out to allow for ridging to build in
next week. This uncertainty will keep a chance of precipitation
going into the weekend and into next week, with precipitation
amounts not expected to produce any significant impacts. The
coldest morning again will be on Saturday, with the best chance
of frost development, and snow levels dropping briefly to 3,000
to 4,000 ft. Afterwards, temperatures and snow levels are
favored to warm/rise slightly (especially if a ridge does indeed
build over the region). The Pacific coast may also see another
round of breezy winds Sunday, but will otherwise remain light.
HPR
&&
.AVIATION...
An upper level trough will form offshore tonight then shift
inland on Thursday. The flow aloft is W to SW. Skies remain VFR
this afternoon and evening with increasing high clouds over
western WA. The flow will turn onshore with the front moving in
on Thursday. The cirrus clouds will be thin enough for patchy
low clouds and fog in the interior again Thursday morning. Low
clouds will burn off by 18-20z. Low level stratus clouds will
increase Thursday night onshore flow. 33
KSEA...VFR tonight with increasing high clouds. Patchy low
clouds in the interior once again Thursday morning with a burn
off by 18-20z. N/NE winds to 5 kt becoming W/SW by 18z Thu to
10 kt. 33
&&
.MARINE...
Weak high pressure will lead to generally light winds over the
waters tonight. Wind and seas will increase on Thursday as a
front moves inland. Highest wind and seas will be over the
Coastal Waters - a Small Craft Advisory is in effect. Expect
building seas to 10-15 ft Thursday night. Winds and seas will
ease and subside on Friday. The flow will turn offshore this
weekend as a deeper surface low spins south over the offshore
waters. The low will weaken as it moves inland early next week.
33
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Small Craft Advisory from 2 PM Thursday to 11 AM PDT Friday
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 from 8 AM Thursday to 5 PM PDT Friday 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