Brier Weather Station
Latitude N 47° 46' 49" Longitude W 122° 16' 48" Elevation 341 ft
850
FXUS66 KSEW 242131
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
231 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/...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 the evening
today, with some 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 is expected to be more limited than Monday
morning, and may not make it east of the Puget Sound. 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 conditions through the afternoon and evening hours. North
to northeast winds through the afternoon, generally around 8 to 12
knots then becoming light southwesterly around 14/15Z. 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. A shift to southwesterly winds in the morning may
help keep the terminal clear. LAMP guidance still indicating around
a 15% chance of ceilings less than 500ft by 13z Tuesday morning,
this will be something to keep an eye on overnight.
&&
.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