Brier Weather Station
Latitude N 47° 46' 49" Longitude W 122° 16' 48" Elevation 341 ft
245
FXUS66 KSEW 231610
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
910 AM PDT Tue Jun 23 2026
.UPDATE...
No changes made to the inherited forecast. The previous
discussion remains below along with an updated aviation section.
&&
.SYNOPSIS...
Upper level ridge over the area today shifting east tonight.
Thermally induced surface trough near the coast this morning
will move inland this afternoon and east of the Cascades
tonight. Increasing low level onshore flow Wednesday. First
weather system in a couple of weeks approaching the coast
Thursday. Front reaching the coast Friday morning moving east of
the Cascades by Friday evening. Cool upper level low dropping
down over the area Saturday. Low moving east Sunday with weak
upper level ridge beginning to build offshore. Weak upper level
trough moving through Monday.
&&
.SHORT TERM /TODAY THROUGH THURSDAY/...
Satellite imagery shows stratus right along the beaches central
and south coast with a few high clouds moving through the area.
Temperatures at 3 am/10z were in the mid 50s to lower 60s
except mid to upper 60s in the Seattle area.
Upper level ridge over the area today. Thermally induced
surface trough near the coast will drift slowly east this
afternoon maintaining low level offshore flow. 850 mb
temperatures rising to plus 16C to 18C this afternoon. Highs
warming into the 80s with the warmer locations like the
Southwest Interior and Cascade Foothills reaching the lower
90s. Afternoon seabreeze kicking in along the central coast
keeping highs in the 70s right along the beaches. Best chance
for a record high today will be at Bellingham.
Upper level ridge moving east of the Cascades tonight. Thermally
induced surface trough also moving moving east of the Cascades
tonight. Low level flow turning onshore along the coast with
light low level flow over the interior. Lows tonight in the mid
50s to lower 60s. Record high minimum temperatures will be
possible over the interior.
Blend has high temperatures Wednesday just a degree or two lower
than Tuesday. Thermally induced trough east of the Cascades
with low level onshore flow to start the day increasing in the
afternoon. Upper level ridge also east of the Cascades with
temperatures aloft cooling. 850 mb temperatures in the plus 14C
to 16C range in the afternoon. Winds in the lower levels also
turning westerly Wednesday morning. Stratus remaining confined
to the coastline but flow aloft turning west southwesterly
pushing some high clouds cover through the area. All these
variables add up to a cooler day Wednesday with highs 5 to 10
cooler than Tuesday, in the mid 70s to mid 80s for the interior.
More cooling along the coast with stronger onshore flow. Highs
on the coast in the mid 60s.
Onshore flow increasing Wednesday night with surface high
pressure building offshore ahead of an approaching weather
system. High clouds continuing to move across the area with
stratus moving inland late. Lows in the 50s.
Front approaching Thursday. Rain out ahead of the system could
reach the coast as early as the afternoon hours. Thickening
cloud cover will keep highs in the 60s and lower 70s.
Heat advisory remaining in effect for all the lowlands except
the coastal beaches today. Cooling Wednesday will drop the
inland coastal areas and the Northwest Interior out of the
advisory. Heat advisory coming to an end for all locations
Wednesday evening. Felton
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
Rain spreading inland Thursday night. Front reaching the coast
Friday morning with the front east of the Cascades by late
Friday afternoon. Rain turning to showers behind the front with
breezy conditions. Post frontal air mass somewhat unstable for
a chance of thunderstorms as well. Convergence zone setting up
probably over Snohomish county in the afternoon and evening
hours. Models are a little weaker with the southerly surface
gradients which brings up the possibility the convergence zone
could end up a little further south over Northern King County.
Cool upper level low dropping down over the area Friday night
into Saturday keeping showers in the forecast. Weak upper level
ridge building offshore Sunday. Weak upper level trough moving
down the backside of the ridge into Western Washington Monday
for a chance of showers.
High temperatures in the upper 50s to mid 60s Friday and
Saturday and only in the 60s Sunday and Monday. There is a
chance for record low maximum temperatures Friday and possibly
Saturday. Felton
&&
.AVIATION...
Primarily VFR conditions are expected with passing high clouds
through the forecast period. There is moderate confidence
(50-60% chance) for IFR conditions to return at HQM Tuesday
evening through Wednesday morning. Winds will generally be out
of the north 5-10 knots for interior terminals and more variable
in direction for the coastal terminals.
KSEA...VFR expected through the TAF period. Northeast winds this
morning 5-8 knots back to the northwest 8-10 knots in the late
morning and early afternoon. Winds become more northerly 6-10 knots
Tuesday night. A return of broader onshore flow on Wednesday will
shift winds to the west-southwest sometime Wednesday morning between
10-14Z.
&&
.MARINE...
Thermally induced surface trough near the coast will drift
slowly east this afternoon moving east of the Cascades tonight.
Low level flow turning onshore along the coast with light low
level flow over the interior. With the thermally induced trough
east of the Cascades low level onshore flow to start the day
Wednesday increasing in the afternoon and evening. A gale watch
has been issued for the Central and Eastern Strait of Juan de
fuca for Wednesday night. Onshore gradients easing Thursday.
Frontal system moving through the waters Friday with possible
small craft advisory winds with and just behind the front. Winds
easing Saturday.
Choppy seas developing over the outer coastal waters tonight
with swell 7 to 9 feet with a 7 to 9 second period. The choppy
seas will continue over the outer coastal waters through
Wednesday night. Felton
&&
.FIRE WEATHER...
High pressure aloft combined with a thermally induced surface
trough over the area will create elevated fire conditions
today. In addition to the warm, dry, and conditionally unstable
air mass, low level offshore flow will drop minimum relative
humidity values into the twenties, and even the teens this
afternoon. The upper level ridge and thermally induced trough
moving east tonight but elevated fire weather concerns could
linger into Wednesday. Fuels are approaching critical levels,
but the main concern remains dry grasses or shrubs, or dead
piles of fuels where brush fires may be able to start (as seen
the last few days). Onshore flow will return with improved low
level moisture Wednesday night and Thursday. Weather system
moving into the area will bring a chance of wetting rains for
the first time in a couple of weeks Thursday night and Friday.
Cool weather will continue through the weekend. Felton
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...Heat Advisory until 11 PM PDT this evening for Eastern Strait
of Juan de Fuca-Foothills and Valleys of Thurston and
Lewis Counties-Foothills and Valleys of the North
Cascades-Foothills of the Western and Southern Olympic
Peninsula-Island County-Lower Chehalis River Valley-
Lowlands of Lewis and Southern Thurston Counties-Lowlands
of Western Skagit and Northwestern Snohomish Counties-
Lowlands of Western Whatcom County-Middle Chehalis River
Valley-Northern Hood Canal-Olympia and Southern Puget
Sound-Port Townsend Area-San Juan County-Southern Hood
Canal-Willapa and Black Hills.
Heat Advisory until 11 PM PDT Wednesday for City of Seattle-
Downtown Everett / Marysville Area-Eastern Kitsap County-
Eastside-Foothills and Valleys of Central King County-
Foothills and Valleys of Pierce and Southern King
Counties-Foothills and Valleys of Snohomish and Northern
King Counties-Lowlands of Pierce and Southern King
Counties-Shoreline / Lynnwood / South Everett Area.
PZ...Gale Watch from Wednesday evening through late Wednesday night
for Central U.S. Waters Strait Of Juan De Fuca-East
Entrance U.S. Waters Strait Of Juan De Fuca.
Small Craft Advisory from 6 PM this evening to 6 AM PDT
Thursday 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