234
FXUS66 KSEW 070331
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
831 PM PDT Tue May 6 2025

.SYNOPSIS...
High pressure will remain in place today, allowing for another
dry and warm day across western Washington. A weak system will
cross the region on Wednesday, bringing in light shower activity
and cooler temperatures. Drier and mild conditions will return
through the remainder of the week, with another frontal system
on track to bring unsettled conditions over the weekend.

&&

.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
An upper level ridge axis will continue to slide eastward today,
bringing in increasing high clouds as the next trough approaches.
A thermally induced surface trough will shift inland throughout
the evening, resulting in elevated temperatures across the
western Washington lowlands. Highs today will reach the upper
60s to lower 70s along the coast and the upper 70s to low 80s
further inland.

Surface flow will shift onshore as a frontal system approaches
the coast. Scattered showers will spread inland overnight and
throughout the day Wednesday, producing periods of drizzle and
light showers. The weakening front will shift inland by the late
afternoon Wednesday with breezy post frontal winds and likely
Puget Sound convergence zone activity continuing into the
evening hours.

High pressure will build into western Washington from the south on
Thursday, allowing conditions to dry out under cloudy skies.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
Little change with the warming trend continuing into Friday.
This will allow temperatures to warm up and peak near the 70
degree mark for much of the interior lowlands on Friday.

Cloud cover will increase across western Washington on Saturday
as the next trough approaches the Pacific Northwest. Chances of
rain increase along the coast heading into Saturday evening,
with the best chance for widespread rain on Sunday as a front
slides across the region. A longwave upper trough will dig
southward just offshore on Monday, maintaining the threat of
shower activity and keeping temperatures on the cool side to
start off next week. Unsettled and cooler conditions will
continue into Tuesday as troughing continues.

15

&&

.AVIATION...
VFR conditions expected through most of the TAF period for most
area terminals, with the exception of the Pacific coast.
Increasing clouds this evening ahead of an incoming frontal
system on Wednesday. Overall not much in the way of precipitation
is expected with drizzle/very light rain Wednesday morning as
the front moves through. Ceilings will lower to MVFR to IFR
along the coast overnight into much of the day on Wednesday,
while in the interior terminals, ceilings do look to lower but
will likely mostly remain VFR to perhaps high-end MVFR at times
if the rain remains intact. Light winds tonight will increase to
west/southwesterly 8 to 15 kt with gusts up to 20 kt possible.
Convergence zone showers are favored to develop behind the front
and linger into Wednesday evening, setting up north of the
Seattle metro.

KSEA...VFR through most of the TAF period. Clouds increasing tonight
with ceilings developing and lowering as a front moves through early
on Wednesday. Light showers/drizzle may promote temporary lowering
to MVFR with the front Wednesday morning but overall low confidence.
Vicinity showers will continue throughout the day Wednesday with
potential for convergence zone showers N of the terminal Wed
evening. Light S wind overnight, becoming SW tomorrow and increasing
Wednesday afternoon to 8 to 12 kt with gusts up to 15 to 20 kt
possible.

62

&&

.MARINE...
Surface high pressure will shift eastward today, maintaining
benign conditions over area waters today. A weak frontal system
will slide eastward throughout the day Wednesday, with a push of
Small Craft winds through the Strait of Juan de Fuca behind the
front Wednesday evening with the strongest winds through the
central Strait. High pressure will rebuild over the region
Thursday through Saturday, allowing for more calm conditions
over area waters. The next system is expected to cross over the
region towards the end of the weekend with unsettled conditions
persisting into next Monday and Tuesday.

Seas generally 5 to 7 feet will rise to 7 to 8 feet on Wednesday.
Seas will ease on Thursday, returning back to 5 to 6 feet through
the weekend.

15

&&

.HYDROLOGY...The daily hydrology discussion has ended until the
start of the next rainy season; it will only be updated if needed.

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Small Craft Advisory from noon to 11 PM PDT Wednesday for West
     Entrance U.S. Waters Strait Of Juan De Fuca.
     Small Craft Advisory from noon Wednesday to 2 AM PDT Thursday
     for Central U.S. Waters Strait Of Juan De Fuca-East
     Entrance U.S. Waters Strait Of Juan De Fuca.

&&

$$