Washington State Forecast Discussion

Western Washington


356
FXUS66 KSEW 262210
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
310 PM PDT Fri Jul 26 2024

.SYNOPSIS...A weak upper level trough remains through the
weekend. A passing front Monday will bring widespread rain chances
to the area, with showers lingering into Tuesday as the upper
trough moves through. Weak high pressure aloft begins to build
again toward midweek.

&&

.SHORT TERM /TONIGHT THROUGH MONDAY/...Weak upper level troughing
over the region this weekend for generally mild conditions.
Temperatures will be close to late July normals. There is a slight
chance of showers in the North Cascades (near the crest) Saturday
afternoon, otherwise the remainder of western WA will be dry.

A deeper trough taps into some moisture over the Pacific on Monday
for wetter and cooler conditions. Much of western WA will see
measurable rain with this system. Up in the mountains, there's a
50-70% chance of seeing wetting rains (at least 0.25").
Temperatures will be cooler and in the 60s. 33

.LONG TERM /TUESDAY THROUGH FRIDAY/...Showers linger on Tuesday as
the upper level trough exits east toward Idaho/Montana. Heights
will build and we'll see a little warming (but still a few
degrees shy of normal). Dry and warmer weather returns mid-week
onwards with broad upper level ridging over the western CONUS.
Temperatures on Thursday and Friday will reach the 80s again
(across the interior lowlands) with pockets of Moderate HeatRisk.
NW flow will keep the coast cooler and in the 60s and 70s. 33

&&

.AVIATION...Northwest flow aloft as subtle ridging resides offshore
along with troughing nearby. VFR across the area as terminals are
under mostly clear skies. Tonight, marine stratus looks to march
inland again but widespread intrusion isn't expected. However, sites
like KSHN, KOLM, etc. could see MVFR to potentially LIFR cigs along
with KHQM into Saturday morning. Stratus will burn off towards the
coast by the afternoon but could still remain around Hoquiam.

KSEA...VFR expected for the remainder of the day and into Saturday.
Surface winds north-northwest 6 to 10 kt this afternoon before
decreasing and veering overnight into Saturday morning.

McMillian

&&

.MARINE...Low-level onshore flow persists with high pressure over
the coastal waters of the Pacific and lower pressure inland. Benign
conditions over the marine zones today. A westerly push through the
strait is certain this evening with a brief 30-40% chance of SCA
level gusts for a few hours. However, not long enough for an
advisory issuance. The next best chance appears to be Saturday night
into Sunday morning for the east and central strait. Marine stratus
will persist in varying coverage for the next several days with
visibility restrictions a possibility over the zones. A frontal
system will move through the region early next week. At this time
the threat for widespread breezy winds impacting small craft is low.

McMillian

&&

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