Brier Weather Station
Latitude N 47° 46' 49" Longitude W 122° 16' 48" Elevation 341 ft
444
FXUS66 KSEW 231025
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
325 AM PDT Thu Jul 23 2026
.SYNOPSIS...
Moisture working its way up into the area from the south will result
in chances for showers and isolated thunderstorms into Thursday. An
upper level trough offshore will then push inland over the weekend,
bringing cooler temperatures to the area and additional chances of
showers. Troughing will persist through early next week, allowing
for temperatures to trend just below to near normal.
&&
.SHORT TERM /TODAY THROUGH SATURDAY/...
An upper-low continues to spin off the OR/CA coast early this
morning - ushering moist, southerly flow aloft into the region.
With it, showers and thunderstorms have been observed but
coverage has waned overnight with loss of diurnal heating. For
today, showers and thunderstorm chances are to continue as the
upper-level pattern remains mostly unchanged. The
aforementioned upper-low will persist offshore along with the
Four Corners High in place, steering south-southwest flow aloft
into western WA. Critical fire weather conditions is favored
due to lightning from thunderstorm activity. Instability will be
harder to come by compared to yesterday as onshore ushers in
marine air. As a result, near- seasonal temperatures are in
store with highs in the upper 70s to lower 80s across the
interior. Coastal areas are forecast to remain in the 60s.
Overnight lows will range between the mid 50s to near 60 F.
Drier conditions and a slight warm up are expected again by
Friday as upper-ridging amplifies subtly. Onshore flow will
allow for the marine stratus to push into the Sound by early
Friday morning but will retreat back to the coast by the
afternoon, allowing for highs across the interior to warm back
into the mid 80s. Highs along the coast will remain cooler under
the marine stratus- and only look to top out in the mid 60s to
low 70s.
Guidance remains in good agreement that the upper level trough
offshore will move across the area over the weekend, which will
bring cooler temperatures and additional chances of showers to
western Washington. The upper-low will begin to progress on
Saturday. As it tracks inland, PoPs are favored to increase
along the coast before spreading inland along the Cascades.
Highs on Saturday are even forecast to top out slightly below
average with highs in the 60s to mid 70s.
41
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
Upper level troughing looks to remain the dominant influence
across the region over the weekend and into early next week.
This will help promote continued onshore flow across the area
and seasonal temperatures with highs in the 70s and lows in the
50s through Wednesday.
&&
.AVIATION...
An upper level low will spin offshore today while
sending mid level moisture and showers over western WA. Highest
chances for thunderstorms will be over the Cascades with showers
fading by 00-03Z this evening. Meanwhile, strong onshore flow in
the lower levels will lead to low clouds and MVFR conditions
this morning. Expect gusty SW winds to 20-25kt over the south
sound through 16Z. 33
KSEA...Low clouds filling in this morning with MVFR conditions
expected. Meanwhile, high-based showers will drift overhead
through 18-21Z. SW wind around 10 kt. 33
&&
.MARINE...
Onshore flow will prevail through the weekend with
strongest winds through the Strait of Juan de Fuca. A front will
stall offshore on Saturday then shift inland Sunday night. 33
&&
.FIRE WEATHER...
Thunderstorm chances will remain into Thursday with the
remnants of tropical storm Elida, which, given the warm and dry
conditions, could cause additional ignitions from lightning.
Rainfall from these storms will mainly be light. A Red Flag
Warning was issued for the southern Cascades, South Sound, and
Olympic Peninsula areas through Thursday night.
Increasing onshore flow beginning later Thursday will bring a wind
shift with breezy southwest winds. This will also produce cooler
temperatures and better overnight RH recoveries through the weekend
into the first part of next week easing fire weather concerns.
FELTON/JBB
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...Red Flag Warning until 10 PM PDT this evening for Black Hills
and Southwest Interior Lowlands-Central Coastal Lowlands-
East Portion of the Olympic Mountains-North Coastal
Lowlands-North and Central Coastal Strip-West Portion of
the Olympic Mountains-West Slopes of the Central Cascades
Generally above 1500 Feet.
PZ...Small Craft Advisory until 5 AM PDT Friday for Central U.S.
Waters Strait Of Juan De Fuca-East Entrance U.S. Waters
Strait Of Juan De Fuca.
Small Craft Advisory until 9 AM PDT this morning for Northern
Inland Waters Including The San Juan Islands-Puget Sound
and Hood Canal.
&&
$$
NWS SEW Office Area Forecast Discussion