Brier Weather Station
Latitude N 47° 46' 49" Longitude W 122° 16' 48" Elevation 341 ft
423
FXUS66 KSEW 250308
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
808 PM PDT Mon Aug 24 2026
.SYNOPSIS...
An upper ridge will remain over Western Washington
through Tuesday bringing dry, warm conditions. Upper low
approaches the area midweek for the return of onshore flow,
cooler temperatures, and chances of precipitation. Upper
troughing will continue to influence the region into next
weekend maintaining cooler, cloudier conditions.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
Hazy skies this evening as smoke from nearby wildfires continues
to filter into Western Washington. Outside of smoke, mostly
clear skies this evening. Otherwise, no major updates to the
forecast. Refer to an updated aviation discussion.
Upper ridging continues to build into the Pacific Northwest
today, with mostly clear skies and warming temperatures. North
winds exist at the surface with more east flow aloft in the mid
levels. The east wind component aloft is allowing for wildfire
smoke from the Cascades to drift into Western Washington this
afternoon. This will continue through midday Tuesday. Onshore
flow resumes later Tuesday, which will push the smoke eastwards
outside of the area by Tuesday night. Otherwise, temperatures
will peak on Tuesday with the ridge axis over the interior Pac
NW, with highs in the 80s to low 90s over Puget Sound, warmest
temperatures in the Cascade Valleys. Moderate HeatRisk is
expected Tuesday for the interior.
An upper low approaches Western Washington on Wednesday, leading
to cooler temperatures and more widespread morning stratus.
Additionally, flow aloft will become more south-southwest, and
will need to monitor the slight chance for thunderstorms in the
North Cascades during the afternoon. Temperatures drop into the
70s to low 80s Wednesday, with 60s along the coast.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
Upper troughing moves across the Pacific Northwest Thursday,
resulting in rain potential for portions of Western Washington,
along with cooler temperatures. Ensembles suggest another trough
moves southwards out of British Columbia overhead late Friday
into Saturday for additional QPF chances and reinforced onshore
flow. Onshore flow then continues early next week. Temperatures
are expected to be below normal during this period, with highs
only in the mid 60s to mid 70s. JD
&&
.AVIATION...
Southwest flow aloft across western Washington with light low level
offshore easterly to northeasterly flow. Widespread VFR conditions
are expected through this evening, with haze aloft from area
wildfires. Another round of marine stratus is expected along the
coast early Tuesday morning with valley fog and shallow stratus
expanding inland. This marine push will be more limited than Monday
morning, and may not make it east of the Kitsap Peninsula. N/NE
winds this afternoon around 8 to 12 knots, easing around 08Z then
becoming light southerly around 14-15Z for many locations south of
the Strait of Juan de Fuca and Skagit County.
KSEA...VFR this evening. North to northeast winds at 8 to 12 knots
become light southwesterly around 14/15Z Tuesday morning. Stratus
and or shallow fog not expected at the terminal into Tuesday
morning. Valley fog may be near, developing again to the east during
the early morning, although probabilities clamp the development of
LIFR visibilities/ceilings at less than 10%. A shift to
southwesterly winds in the morning may help keep the terminal clear.
15/HPR
&&
.MARINE...
Surface high pressure remains over the coastal waters into
Tuesday. North winds will increase along the coastal waters this
afternoon and evening, with periodic Small Craft Advisory wind
gusts. A thermal trough along the coast will slide inland on
Tuesday, with increasing onshore flow into Wednesday. A westerly
push is expected through the Strait of Juan de Fuca Tuesday
evening. Probabilities for SCA wind gusts in the Strait during
this period range 60 to 90%, and for this reason a Small Craft
Advisory has been issued. Otherwise, winds transition to the
south and southwest for all waters midweek. Onshore flow then
continues through late week, with periods of stronger west winds
through the Strait of Juan de Fuca.
Seas of 4 to 6 feet for the majority of the week. Seas may be
choppy through this evening for the coastal waters due to a
period of around 6 seconds. JD
&&
.FIRE WEATHER...
A warming and drying trend will continue through Tuesday as a
thermal trough builds northward along the coast. Offshore
easterly flow will strengthen tonight into Tuesday, promoting
additional drying near the Cascade gaps, where relative humidity
values are expected to drop to near critical values in the low
to mid 20s on Tuesday. Elevated fire weather conditions will
continue through Tuesday for these areas.
A pattern change late Tuesday into Wednesday will bring the return
of moist onshore flow, cooler temperatures, and chances of light
precipitation through the remainder of the week, mitigating fire
weather concerns for most areas. Isolated thunderstorms along the
coast and over higher terrain are possible with each round of
moisture, though the exact details remain somewhat uncertain.
Upper level troughing is favored to remain over the Pacific
Northwest over the weekend, with continued onshore flow, excellent
overnight relative humidity recoveries, and cooler temperatures.
Chances for thunderstorms continue into the weekend, with around a
15-25% chance across both the mountains and lowlands.
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Small Craft Advisory from 5 PM Tuesday to 2 AM PDT Wednesday
for Central U.S. Waters Strait Of Juan De Fuca-East
Entrance U.S. Waters Strait Of Juan De Fuca.
Small Craft Advisory until midnight PDT tonight 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.
&&
$$
NWS SEW Office Area Forecast Discussion