986
FXUS66 KSEW 150426
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
826 PM PST Tue Jan 14 2025

.SYNOPSIS...Another round of morning fog and low stratus expected
Wednesday as high pressure continues to persist over Western
Washington. A weak system on Thursday will bring back light
precipitation chances. Colder and drier conditions will persist
through early next week as high pressure rebuilds on Friday.

&&

.SHORT TERM /TONIGHT THROUGH SATURDAY/...No changes from the
previous forecast. 33

Previous discussion...Some locations across Western Washington
have managed to clear out the fog (along the coast and north of
Everett); however some locations along Puget Sound are still
experiencing reduced visibilities. High pressure continues to
dominate over Western Washington, which will bring another round
of morning fog and low clouds Wednesday morning. across the
interior lowlands and coast. A shift in the weather pattern on
Thursday as a weak system will move through the area. Some light
showers are possible along the north coast; however the majority
of the precipitation (light mountain snow) will be concentrated
along the North and Central Cascades. No significant impacts are
expected.

A colder and drying trend begins on Friday as high pressure
rebuilds over the Pacific Ocean. Patchy fog possible Friday
morning. High temperatures will be in the mid to low 40s; low
temperatures will be in the 30s.

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...Cold and dry conditions
will continue through the weekend and early next week with high
pressure building offshore. High temperatures through Monday are
expected to be in the low 40s, and low temperatures will be in the
low to mid 20s. With a colder airmass in place and temperatures
below freezing, fog formation will be limited.

The deterministic NBM hints at the possibility of precipitation
returning on Tuesday in the form of light rain/snow showers for
the coast and some of the lowlands. Model guidance also hints at
some light precipitation returning on Tuesday, but in the form of
rain. PoPs on Tuesday range between 20-25%. High temperatures
will be in the 40s and low temperatures in the mid to upper 20s.

MGF

&&

.AVIATION...Northwest to westerly flow remains over western
Washington as an upper level ridge moves over the region. Low
clouds, with IFR to LIFR cigs, remain in place over the central
Puget Sound area and along the Strait of Juan de Fuca this
evening.

Light winds will continue tonight into Wednesday, allowing for
ceilings to once again re-develop and drop to LIFR and fog to
redevelop by the early morning hours. Clearing will once again be
slow but models are trying to hint that clearing may be possible
Wednesday afternoon with less upper level cloud cover, but with
such light wind at the surface, it is plausible that the central
Puget Sound area once again never fully clears out before high
clouds fill in ahead of the next system coming in early Thursday.

KSEA...LIFR conditions with low stratus over the terminal. Light
surface flow will not allow for rapid changes, but expect ceilings
to remain LIFR/IFR into Wednesday morning. Clearing will once
again be slow, but ceilings may be able to break up faster, with
improving conditions as early as around 21-22Z Wednesday. Winds
will remain light north/northeasterly, around 4 kt or less through
the TAF period.

62/Mazurkiewicz

&&

.MARINE...A surface ridge over the coastal waters will shift inland
Wednesday night, maintaining weak northeasterly winds. A weak
frontal system will move through the region on Thursday morning.
Stronger high pressure will build in its wake on Thursday for
stronger northwesterly flow over the coastal waters and an onshore
push through the Strait of Juan de Fuca which may prompt additional
headlines. Building high pressure over southern British Columbia and
east of the Cascades will lead to a return to offshore flow late in
the week.

Seas remain around 10 ft through the outer coastal waters through
tomorrow afternoon, for which a Small Craft Advisory remains in
effect. Seas will likely rise above 10 ft again with the frontal
passage Thursday before subsiding this weekend into the beginning of
next week.

62/27

&&

.HYDROLOGY...No river flooding the next seven days.


&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Small Craft Advisory until 4 PM PST Wednesday for Coastal Waters
     From Cape Flattery To James Island 10 To 60 Nm-Coastal
     Waters From James Island To Point Grenville 10 To 60 Nm-
     Coastal Waters From Point Grenville To Cape Shoalwater 10
     To 60 Nm.

&&

$$