738
FXUS66 KSEW 260419
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
919 PM PDT Sat May 25 2024

.SYNOPSIS...Showery and cooler conditions will continue into
Sunday as an upper level trough moves through the region. Upper
level ridging will slowly begin to build east of our area through
Monday for slightly warmer temps, with troughing over the Pacific
still keeping an influence over western Washington. A frontal
system will move through on Tuesday for another bout of rain and
cooler temperatures.

&&

.SHORT TERM /TONIGHT THROUGH WEDNESDAY/...Radar imagery continues
to show isolated showers across western Washington, particularly
over the Cascades, the Pacific Coastal regions, and through the
northern Hood Canal up towards Port Townsend. These showers are
being forced by a weak departing upper-level trough. Low
temperatures tonight into the upper 40s.

A weak frontal system will eject from a large upper level trough
in the Gulf of Alaska and move through the northern part of our
area tomorrow, weakening as it does so. The North Coast, the
Northwest Interior, and the Cascades will receive the bulk of the
rain, leaving only a few light showers with minimal accumulations
expected for the remained of the region. Mostly dry conditions are
expected south and east of Seattle. High temperatures similar to
today, in the mid to upper 50s.

An upper level ridge will start to build east of our area, in the
Interior West, while broad troughing offshore will remain close
enough to keep an influence over western Washington. Temperatures
will also warm up a little on Memorial Day, with high temps in the
upper 60s in the interior lowlands, while locations near the
water will be in the lower 60s. Shower chances increase through
the evening and into Tuesday morning as a frontal system
approaches the area while the upper trough digs southward. Showers
will start to push in through the interior Tuesday afternoon and
largely continue into Wednesday.

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...Extended ensemble
guidance agrees on upper level troughing continuing through
late Wednesday, with showers decreasing in coverage on Thursday.
Cluster guidance are in agreement on an upper level ridge
building offshore western Washington into the weekend, providing
drier and warmer conditions.

Mazurkiewicz/LH

&&

.AVIATION...Westerly flow aloft with a weak warm front moving over
the area Sunday. Low level onshore flow continuing through Sunday.
Ceilings mostly low end VFR tonight into Sunday morning. MVFR
ceilings around KPAE due to some weak convergence. Ceilings
lowering to MVFR with isolated IFR ceilings 12z-16z. MVFR ceilings
continuing into Sunday afternoon with slow improvement to VFR
after 22z as front lifts north into Southern British Columbia.

KSEA...VFR into the early morning hours. Ceilings lowering to MVFr
after 09z with ceilings continuing to lower down to near 1000 feet
11z-14z. MVFR ceilings continuing into Sunday afternoon with slow
improvement after 22z and VFR ceilings after 03z. Southerly winds
6 to 10 knots increasing to 10-15 knots with gusts 20-25 knots
after 18z. Felton

&&

.MARINE...Onshore flow will ease tonight with with small craft
advisory winds for portions of the Strait of Juan de Fuca coming
to an end by midnight. A warm front will brush the area on Sunday
then lift north into southern B.C. Sunday afternoon and evening.
Another frontal system will cross western Washington on Tuesday,
followed by onshore flow Tuesday night and Wednesday.

33/Felton

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Small Craft Advisory until 11 PM PDT this evening for Central
     U.S. Waters Strait Of Juan De Fuca-East Entrance U.S.
     Waters Strait Of Juan De Fuca.

&&

$$