Brier Weather Station
Latitude N 47° 46' 49" Longitude W 122° 16' 48" Elevation 341 ft
093
FXUS66 KSEW 250943
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
243 AM PDT Thu Jun 25 2026
.SYNOPSIS...
A significant change in the weather pattern will begin to take
place today. A frontal system will arrive early Friday and will
be followed by a cool and unsettled period across Western
Washington that will persist into the middle of next week.
&&
.SHORT TERM /TODAY THROUGH SATURDAY/...
After an extended period of time in which 12 of the past 13 days
featured above normal temperatures and an absence of any
measurable precipitation, we`re in for a major shift in the
weather pattern beginning today. Stratus is creeping inland from
the coast and will reach at least some of the interior lowlands
by daybreak. The accompanying marine air mass will knock 10 to
20 degrees off high temperatures across interior lowland
locations over those of yesterday with mid and level clouds
steadily increasing throughout the day. Some light rain ahead
of an approaching front will reach coastal areas by late
afternoon or early evening. It`ll likely be slow to spread
inland to Puget Sound, but we should see a few showers around by
early Friday morning as a dissipating front drags itself slowly
inland.
After a sojourn at or near record high temperature territory in
recent days, Seattle will probably only narrowly miss a record
low maximum on Friday. Hope you kept your hoodie near the front
of the closet. A post-frontal convergence zone is likely to form
Friday afternoon and evening. Thunder chances look fairly
slim during the period...mainly 10 to 20 percent. The
convergence zone will diminish by early Saturday as an upper low
closes off and gradually shifts southward along the coast. It
will, however, remain unsettled on Saturday with shower chances
in the forecast as moisture wraps around the low just offshore.
Temperatures will be held below seasonal norms for a third
consecutive day.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
Looking ahead into the early portion of next week, cooler and
unsettled conditions are likely to stay in the picture. Model
ensembles maintain a general mean upper trough position over
the western third of the lower 48 with upper ridging centered
well offshore around 150 W. While not a particularly wet
scenario, it keeps onshore flow in place with heights never
really recovering much. That keeps temperatures a little below
average, skies a little gloomier, and a lingering threat of
showers in the forecast now and then. Longer term ensembles
point toward a warming trend...after the 4th. Ah, a small taste
of normality.
27
&&
.AVIATION...
Onshore flow has brought IFR stratus to coastal terminals early this
morning with nighttime microphysics satellite showing marine stratus
spreading inland. The arrival of high level clouds will make it
difficult to monitor trends over the next couple of hours, but
expecting stratus to fill into SEA/BFI around 13Z. Winds will remain
out of the south-southwest 5-12 kt, except for near the Strait of
Juan de Fuca where winds will be 10-15 kts with gusts up to 25-30
kts through 20z Thursday. A warm front approaches the coast
Thursday, with showers increasing as early as 18Z for the coast.
Showers become more widespread over western WA by 03Z Friday.
KSEA...VFR conditions initially with moderate confidence (50% chance)
for ceilings to drop below 2000 feet between 13-17Z before lifting
after 17Z. Isolated showers Thursday afternoon will become more
widespread in the evening. Conditions are expected to remain VFR
through 05Z Friday, with MVFR probabilities increasing from 20% at
05Z to 60% by 12Z. Winds expected to remain out of the southwest at
5-10kt through most of the period. West/southwest winds will pick up
after 00Z Friday with gusts up to 20 kts.
&&
.MARINE...
High pressure will weaken over the coastal and offshore waters
today as a weak surface low and associated frontal system
approach the north end of Vancouver Island. The front will move
onshore across Western Washington on Friday morning then
gradually dissipate as it moves inland. A broad area of weak low
pressure will remain over the inner coastal and inland waters
into Saturday while high pressure begins to rebuild well
offshore. This will likely lead to gusty northwesterly winds
over the outer coastal waters along with increasingly choppy
seas building to 8 to 10 feet.
Varying degrees of onshore flow can be expected for the first
half of next week as low pressure remains in place east of the
Cascades with broad surface high pressure anchored well
offshore.
27
&&
.FIRE WEATHER...
Cooler and wetter conditions will prevail beginning today and
persist into early next week that will limit fire weather
concerns. There is a low end chance of thunder (10-20%) on
Friday, but is likely to be accompanied by wetting
rain...especially in and around the convergence zone and in the
higher elevations of the Cascades.
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Small Craft Advisory until 11 AM PDT this morning for Central
U.S. Waters Strait Of Juan De Fuca-East Entrance U.S.
Waters Strait Of Juan De Fuca.
&&
$$
NWS SEW Office Area Forecast Discussion