142
FXUS66 KSEW 251623
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
923 AM PDT Wed Jun 25 2025

.SYNOPSIS...Upper level trough over Western Washington through
Friday. Weak systems crossing the area each day will bring at
least a chance of showers. Best chances for measurable rain
Thursday. Upper level ridge building over the weekend for drier
and warmer weather. The ridge will slowly move east Monday and
Tuesday but temperatures will remain above normal.

&&

.UPDATE...It`s a quiet morning across the region. Stratus is
solidly in place which will limit daytime heating. Highs today
will top out today in the 60s to perhaps close to 70. The
current forecast is on track an no updates are planned.
-Wolcott-

&&

.SHORT TERM /TODAY THROUGH FRIDAY/...Satellite imagery shows
stratus surging inland over the Southern and Central Puget Sound
while to the north the stratus is not even half way down the
Strait of Juan de Fuca at 10z/3 am. A middle level cloud deck is
also over the Northwest Interior. Temperatures were in the
lower to mid 50s.

Weak upper level trough over Western Washington today will remain
in place through Friday. Shortwaves moving through the area about
every 24 hours. The first one today will not produce much in the
way of rain showers. Best chance for showers near the Canadian
border. Under cloudy skies highs much cooler than Tuesday, in the
60s.

Next shortwave moving through Thursday. This will be the strongest
one in the series with measurable rain along the coast and over
the northern half of the area. Chance of showers over the southern
half of Western Washington. High temperatures cooling a little bit
more, in the lower to mid 60s. The record low maximum temperature
for Seattle is 62 degrees set in 1999. Will be close to the record.

Last shortwave in the series moving through Friday morning into
the afternoon hours. This one will be similar to the one today
with a little more northerly track. For now will keep pops out of
the Southwest Interior with just slight chance to chance pops
elsewhere. Highs once again below normal, in the 60s.

.LONG TERM /SATURDAY THROUGH TUESDAY/...Extended models remain in
good agreement with an upper level ridge beginning to build
Saturday. The ridge will continue to build Sunday with 500 mb
heights in the mid 580 dms by 00z Monday. Ridge begins to slide
east Monday in response to a weak upper level trough offshore.
Ridge well to the east Tuesday with zonal flow aloft. Even with
the ridge axis to the east upper level temperatures not cooling
much with 500 mb heights still in the lower 580 dms.

Warming trend beginning Saturday with highs in the mid 60s to mid
70s. Highs Sunday in the 70s to lower 80s. Highs peaking Monday
in the mid 70s to mid 80s for the interior with slight cooling, a
couple of degrees, for Tuesday. Low level flow never really turns
offshore. Because of this afternoon seabreezes will keep highs in
the mid 60s to lower 70s along the coast. Felton

&&

.AVIATION...Low-end MVFR and IFR ceilings expected to persist this
morning. Stratus will lift to VFR and gradually scatter (to some
degree) after 20-22z this afternoon. Terminals along the coast
(KHQM) and Strait of Juan de Fuca (KCLM) will likely not improve
into VFR and remain at MVFR. Light scattered showers/drizzle
possible today; however, confidence is low on which terminals will
be impacted and did not add to the prevailing line. Otherwise, VFR
will prevail into the evening hours. Lowered ceilings, widespread
MVFR returns overnight/early Thursday morning, with IFR along the
coast.

KSEA...MVFR conditions this morning, with improvement to VFR
expected after 20-21z this afternoon. VFR is favored to prevail
throughout the evening. Another round of low stratus returns early
Thursday morning between 9z-11z, with ceilings lowering down to
MVFR. SW surface winds 5-10 kt for of the upcoming period.

McMillian/29

&&

.MARINE...Onshore flow persisting the next several days,
with westerly pushes through the Strait of Juan de Fuca each evening
of varying strength with none near SCA levels. A weak disturbance is
moving across waters today, but headlines aren`t favored. High
pressure will rebuild over the waters late in the week into the
weekend, with northwest flow establishing over the coastal waters.
Seas will generally be around 3-4 ft throughout the week and will
increase slightly into the weekend to 4-6 ft.

McMillian

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...None.

&&

$$