000
FXUS66 KSEW 110344
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
844 PM PDT Wed Apr 10 2024

.UPDATE...Low temperatures likely a bit warmer tonight, in the low
40s, with increasing cloud cover ahead of the next frontal system
tomorrow. Satellite imagery shows the next front just offshore as
it works its way into the region. No updates this evening, the
forecast is on track. See below for updated aviation and marine
sections. LH

&&

.SYNOPSIS...The next front crosses the region Thursday, with some
rain and mountain snow returning. Dry and mild conditions are
expected much of the weekend with weak high pressure in place, but
a stronger front will bring a return of rain, mountain snow, and
cooler conditions for the start of next week.


&&

.SHORT TERM /TONIGHT THROUGH SUNDAY/...High pressure brings dry
weather to western WA today with temperatures in the 50s. Areas
around the south sound may see lower 60s this afternoon.

Rain returns to western WA on Thursday as the ridge slides east
and a trough digs offshore. The front weakens/dissipates as it
moves inland and much of the interior will not see rain until the
late afternoon and early evening. Snow levels stay over 4000 ft
so just a few inches of snow over the higher mountain peaks.

The offshore trough will continue to dig south on Friday with a
closed low moving into California over the weekend. This patterns
pulls moisture away from western WA for a dry forecast (aside from
a few lingering showers in the Cascades on Friday). Temperature-
wise, we`ll see highs in the lower to mid 60s in the interior with
cooler 50s along the coast (with plenty of sunshine). 33

.LONG TERM /MONDAY THROUGH THURSDAY/...Western WA remains in
between weather systems on Sunday with low pressure over
California and northern B.C. We will see increasing onshore flow
and more cloud cover compared to Saturday, though. Temperatures
will continue to track a few degrees warmer than average with
highs in the lower 60s in the interior.

The weather pattern turns cooler and wetter early next week as
the B.C. trough dips south into the region. Snow levels will be
lower with this trough, around 2000 ft, with a few inches of snow
at the highway passes. Temps will track cooler than average with
lows in the 30s to lower 40s (and temps near freezing around the
south sound Tuesday morning). Dry and warmer weather looks to
return midweek onwards with a ridge over the NE Pacific. 33

&&

.AVIATION...Low amplitude upper ridge will continue to shift
eastward tonight with westerly flow aloft becoming southwesterly
as a weak front approaches the region. VFR conditions expected
areawide with plentiful high level moisture streaming overhead.
Ceilings will gradually lower overnight and start to become MVFR
along the coast between 12Z-15Z Thursday as rain arrives ahead of
the incoming front. These conditions will then slowly spread to
interior areas Thursday afternoon, likely between 21Z-00Z.

KSEA...VFR with high clouds this evening. Ceilings lowering
overnight and becoming MVFR in light rain at times by Thursday
afternoon. Surface winds N/NW generally under 7 knots tonight
will back to light southerly by early Thursday increasing to 8 to
12 knots Thursday afternoon. 27/14

&&

.MARINE...Weak high pressure over the coastal waters shifts inland
tonight then weak front arrives on Thursday with winds remaining
under advisory levels. Surface ridging will return over the waters
until the end of the week and looks to bring breezy northerlies over
the offshore coastal waters into the weekend. Another front arrives
on Monday.

Seas over the coastal waters will hover between 5-8 feet the next
few days, before increasing towards 7-9 feet Friday night into
Saturday. Seas then look to briefly subside Sunday before building
and approaching 10 feet early next week. 27/14

&&

.HYDROLOGY...No river flooding is expected through the next seven
days.

&&

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

$$