Brier Weather Station
Latitude N 47° 46' 49" Longitude W 122° 16' 48" Elevation 341 ft
292
FXUS66 KSEW 191115
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
315 AM PST Wed Nov 19 2025
.SYNOPSIS...
High pressure will move inland today, with some patchy areas of
dense fog this morning across the region. Some breezy east gap
winds are expected in the Cascades as well today. The
progressive pattern continues with a weak front bringing some
showers tonight into early Thursday. A stronger system will
bring precipitation this weekend into next week. This next set
of systems looks to add substantial rainfall and accumulating
snow in the mountains. Cooler temperatures are expected going
into next week
&&
.SHORT TERM /TODAY THROUGH FRIDAY/...
An upper level ridge currently sits over western WA this
morning. High pressure is centered underneath at the surface in
southern B.C. Canada. Quite a bit of clear skies last night
(combined with the weak flow aloft and lack of a dew point
spread with the cool temperatures in the 30s this morning) has
led to patchy to widespread areas of dense fog this morning. The
areas with the lowest visibilities (1/4 mile) will be monitored
for possible dense fog advisories (in time for the morning
commute). The foggiest areas are expected to be primarily along
the I-5/I-405 corridors (as well as the Kitsap Peninsula).
The high pressure/ridge will shift inland today, with a frontal
system approaching the coast later tonight. The increased
pressure gradient is expected to produce breezy east winds, with
gusts of 25-35 mph at times today. An isolated pocket of 35 to
45 mph winds is expected in the North Bend area today (and the
wind advisory for the area will continue). The coast and east
Strait of Juan de Fuca areas may also see some gusts of 20 to 30
mph at times later today.
The previous mentioned front will split as it moves ashore, and will
bring showers along the coast late tonight/Thursday morning.
The coast is favored to see the most amount of QPF with this
system (which is a light 0.25" or so of rain), while remaining
areas see a few hundredths to a tenth of an inch. The
precipitation drops to less than 30% chance the remainder of
Thursday. Some areas of patchy fog will be possible again
Thursday morning, potentially lingering for a good part of the
day. Winds are expected to remain light on Thursday. Overnight
temperatures will improve with increased cloud coverage (low 40s
in the lowlands). Highs remain in the low 50s.
In addition to showers: along the coast, large long-period waves
are expected to arrive Thursday afternoon. The latest
NWPS/ensemble model guidance has waves approaching 14 to 16 ft
Thursday afternoon with periods around 14 to 16 seconds. A
future high surf advisory may be needed for the threat of beach
erosion and significant run-up.
For Friday: This is the beginning of what is expected to be a
series of progressive systems moving through the region into the
weekend and next week. A front arrives Friday afternoon with
increasing chances of precipitation. Snow levels will remain
elevated around 6,000 ft. during the day, keeping initial
significant snowfall to the peaks of the highest north Cascades
peaks. The hydrologic concerns remain low at this time (see
hydrology discussion below).
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
As mentioned, the progressive pattern is expected to continue
through the weekend into next week. The heaviest of the QPF has
shifted into Sunday-Monday night, but remains in the Cascades
and in the Olympics/coast. Snow levels are expected to drop
down to around 2,000 ft going into Tuesday. Accumulating snow
will be possible at some of the more popular passes (Stevens,
and Snoqualmie). Please continue to monitor travel conditions
going into next week (especially if traveling for the
Thanksgiving holiday).
Ensembles are split going into the middle of next week on if the
pattern will become warmer or cooler (although CPC has western
WA in a slight chance of below average temperatures next 8-14
days). The deterministic forecast favors cooler temperatures
going into next week, with a few more lows in the 30s by midweek
next week. Highs Tuesday only reach the upper 40s for most urban
areas. Precipitation chances remain around 20% going into the
middle of the week, but depending on how cool the air will get,
any showers that do form during the cold hours will have the
chance to mix a few snowflakes down to the surface.
HPR
&&
.AVIATION...
An upper ridge continues to remain over the region today with weak
offshore flow developing this afternoon. With clearing of mid/high
clouds, light wind, and abundant low level moisture lingering, fog
and low clouds will increasingly fill in early this morning. Expect
fairly widespread IFR or lower ceilings with areas reduced surface
visibility for most of the interior lowlands 12-17z. Low level
offshore flow will begin to develop on Wednesday and this should
help gradually erode the low clouds late morning onward for a return
to VFR for most areas by early afternoon. Increasing mid/high clouds
late tonight/early Thursday ahead of the next frontal system.
KSEA...Weak surface winds overnight combined with some clearing and
saturated low levels maintain high confidence in the development of
fog and low clouds this morning. Expect lowest conditions by 12-13z
through 17z. Fog and low clouds may hang on into late morning before
low level easterly flow breaks through near-surface inversions and
provides some lifting ceilings. Light winds will increase to around
5-7 kt from the east/northeast by late morning, increasing to 10-15
kt this afternoon. 12
&&
.MARINE...
High pressure will shift inland today, with a weak front
expected to split moving across the waters/land
tonight/Thursday. Some patchy dense fog is possible in the Puget
Sound this morning. Otherwise. breezy east winds will turn more
south/southeast later today ahead of the next front. Small craft
advisories continue for the coastal waters, and the west/east
Strait of Juan de Fuca areas for wind gusts up to 25 mph (up to
30 mph in the east strait). This progressive weather pattern is
expected to continue through the weekend into next week, as
models try to solve different paths for several systems expected
to pass through our region.
Seas of 8 to 10 ft are expected in the outer coastal waters
today (6 to 8 ft in the inner coastal waters). An increasing
westward component will bring seas of 15 to 18 ft close to the
shore, before dropping to 8 to 12 ft into early next week,
decreasing to 8 to 10 ft.
HPR
&&
.HYDROLOGY...
No flooding is expected through the week ahead. Stronger weather
systems moving into the region early next week could bring periods
of heavier rain (or mountain snow) and will be the next time frame
to watch with respect to hydrologic concerns.
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...Wind Advisory from 10 AM this morning to 10 PM PST this
evening for Foothills and Valleys of Central King County.
PZ...Small Craft Advisory from 7 AM this morning to 4 AM PST
Thursday 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 Point
Grenville To Cape Shoalwater 10 To 60 Nm-West Entrance
U.S. Waters Strait Of Juan De Fuca.
Small Craft Advisory from 6 PM this evening to 10 AM PST
Thursday for East Entrance U.S. Waters Strait Of Juan De
Fuca.
Small Craft Advisory from 10 AM this morning to 4 AM PST
Thursday for Coastal Waters From James Island To Point
Grenville Out 10 Nm-Coastal Waters From Point Grenville
To Cape Shoalwater Out 10 Nm.
&&
$$
NWS SEW Office Area Forecast Discussion