844
FXUS66 KSEW 090353
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
853 PM PDT Tue Oct 8 2024

.UPDATE...Weak shortwave slowly moving through Western Washington
this evening. Doppler radar has showers along a line from about
Bellingham to Hoquiam. The shortwave will move into the Cascades
in the early morning hours Wednesday. Increasing onshore flow
behind the shortwave with a convergence zone over Snohomish and
Northern King county Wednesday morning. Another weak shortwave
arriving Wednesday night keeping a mention of showers in the
forecast. Current forecast has the trends covered. Previous
discussion follows with updated aviation and marine section.
Felton

&&

.SHORT TERM /TONIGHT THROUGH FRIDAY/...An area of showers is
pushing across the Olympic Peninsula and north interior early this
afternoon. This feature will also dissipate and weaken as it
moves across the Cascades late tonight. However, right on it`s
heels, the next wave will lift northeast across the Pacific
Northwest bringing yet another chance for light precipitation,
primarily to the northern 2/3rds of the CWA Wednesday afternoon
though Wednesday night.

Longwave ridging is expected to develop along the west coast late
Thursday into Friday, resulting in drier conditions and the
beginning of a slow warm up.

.LONG TERM /SATURDAY THROUGH TUESDAY/...The aforementioned high
pressure will continue to build through at least Saturday and
perhaps Sunday, allowing temperatures to continue to warm to above
normal (upper 60s and low 70s). The only wrinkle is a compact low
pressure system that is most likely to drift across Oregon under
the ridge which could complicate the forecast slightly.

By early next week, this ridge axis is likely to shift east of the
area and a longwave low pressure system will inch closer to the
west coast, opening the door once again for precipitation and
cooler weather. At this time, there is no signal for significant
weather impacts over the next 7-10 days.
-Wolcott-

&&

.AVIATION...Southwest flow aloft as broad troughing
situates itself over western Washington. A mixed bag of conditions
out there this evening with MVFR throughout most of the interior,
with spots of IFR/LIFR in localized spots such as KHQM and KCLM.
Rain showers will remain this evening along with low stratus
continuing overnight into Wednesday morning.

KSEA...MVFR conditions this evening at the terminal. Low clouds and
MVFR will continue late tonight into Wednesday morning with a 25-30%
chance of IFR ceilings being bet. S/SW winds will continue generally
around 5 to 10 kts.

Mazurkiewicz/McMillian

&&

.MARINE...A weak front has exited the coastal waters earlier this
afternoon with generally onshore flow in its wake. Generally benign
conditions across the waters, with another frontal system crossing
the area late Wednesday, but holding no wind or sea impacts.

Seas will generally maintain 6 to feet through midweek, before
decreasing to 4 to 6 feet over the weekend.

Mazurkiewicz

&&

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

$$