-- Discussion containing changed information from previous version are highlighted. --
894
FXUS66 KSEW 182143
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
243 PM PDT Wed Jun 18 2025

.SYNOPSIS...
-- Changed Discussion --
Showers in the Cascades will decrease tonight. A deep
upper low will spin offshore on Thursday. Showers will increase
Friday and Saturday as the low moves inland. Mountain snow showers
are also expected above 5000 feet. Warmer and drier conditions
will return by early next week.
-- End Changed Discussion --

&&

.SHORT TERM /TONIGHT THROUGH SATURDAY/...
-- Changed Discussion --
We`re in post-frontal
onshore flow this afternoon with showers mostly focused over the
Cascades. Winds are a little gusty in the south sound (SW gusts to
20-25 MPH) but will ease this evening.

Thursday is mainly dry as an upper level low slowly wobbles south
off southern B.C. Winds are lighter overall and temperatures will
track close to average.

Showers increase on Friday as the upper low starts to shift east
and inland. The air mass is slightly unstable for a chance of
afternoon thunderstorms in SW WA. Friday will be cooler too with
highs around 60 degrees.

The air mass will be cool and showery moving into Saturday with
the upper low overhead. Snow levels in the mountains are down to
around 5000 ft with a few inches of snow on the higher peaks. The
morning and early afternoon will be wet with 0.25-0.50" rainfall
ranges across the lowlands. And like Friday, peak temps are only
around 60s, well below average. 33

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...The upper low shifts
farther E/NE on Sunday and weakens, with broad troughing over the
Pac NW. There will be lingering showers but mainly light and not
as wet compared to Friday-Saturday. We`re back to a warm and dry
pattern through Wednesday with high pressure. Temperatures will
reach the lower 80s again in the interior. The coast will be
cooler and in the 60s with northwest flow. 33
-- End Changed Discussion --

&&

.AVIATION...
-- Changed Discussion --
Southwest flow aloft as an upper-trough hovers over the
region. Low-level onshore flow increasing into the evening and
remaining throughout the TAF period. VFR cigs this afternoon are
likely to remain overnight into Thursday morning. Isolated MVFR to
IFR possible during this time, mainly along the coast (KHQM). Gusty
SW winds up to 25 kt diminishing after 00z Thursday. Winds will
relax tonight before increasing again Thursday afternoon.

KSEA...VFR currently and should remain throughout the remainder of
the TAF period.  Southwest wind 10 to 15 knots with gusts 20 to 25
knots through 00z Thursday. Winds easing back down to 6 to 10 knots
after 00z before going variable then trending more southerly less
than 5 knots after 06-08z. Winds turn more NW Thursday afternoon 5-
10 kt.
-- End Changed Discussion --

&&

.MARINE...
-- Changed Discussion --
We`re post-frontal across area waters this afternoon.
Surface high pressure building offshore is increasing low-level
onshore flow. As a result, a SCA remains in effect for
central/eastern strait tonight. Gusts could get near Gale Force this
evening. More westerly pushes Thursday night and Friday night also
strong enough for small craft advisory westerlies in the Central and
Eastern Strait as well. High pressure will weaken on Thursday night
as the next disturbance enters Friday into Saturday.

Seas varying between 3 to 6 ft throughout much of the week before
increasing to 5 to 8 ft on Saturday.

McMillian
-- End Changed Discussion --

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
WA...None.
PZ...Small Craft Advisory until 3 AM PDT Thursday for Central U.S.
     Waters Strait Of Juan De Fuca-East Entrance U.S. Waters
     Strait Of Juan De Fuca.
-- End Changed Discussion --

&&

$$