548
FXUS66 KSEW 050350
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
850 PM PDT Fri Apr 4 2025

.UPDATE...Dry conditions into Saturday with upper ridging across
the Pacific Northwest. High clouds at times tonight will likely
limit any fog extent, although localized fog may develop mainly
around Olympia. No forecast updates this evening.

&&

.SYNOPSIS...High pressure will build into the region through the
remainder of the week, allowing conditions to dry out and warm up.
Wet and cooler conditions are on track to return towards the end
of the weekend and continue through mid-week as troughing settles
into the Pacific Northwest.

&&

.SHORT TERM /TONIGHT THROUGH TUESDAY/...Dry and mild weather
prevails moving into the weekend thanks to high pressure.
Temperatures are in the 50s and lower 60s this afternoon with
plenty of sun. High clouds will move in tonight and we should see
warmer overnight lows (no more frost and low 30s like this
morning). Saturday will be mild and in the 60s to lower 70s, with
a mix of mid and high clouds aloft.

The upper level ridge will shift east on Sunday while a trough
digs offshore. Rain with a cold front will reach the coast during
the morning with rain spreading inland during the late morning and
afternoon. Snow levels remain high for mostly rain in the
mountains and passes.

Showery weather extends into Monday with a trough overhead. The
air mass will be cooler with snow levels lowering from around 5500
to 3500 ft. Snow amounts are highest over the volcanoes with just
an inch or less at the Cascade passes. 33

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...Washington remains under
moist, W to SW flow, moving through next week, with additional
rounds of rain and mountain snow. Temperatures will track close to
average with lows in the 40s and highs in the mid to upper 50s.
The coast may see over an inch of rain through the period, where
72-hour rain total probabilities are over 90 percent. Heavy
rainfall in the Olympics may also force sharp rises on the
Skokomish River in Mason County - near minor flood stage. 33

&&

.AVIATION...Northerly winds aloft becoming westerly tonight as an
upper level ridge moves across western Washington. VFR conditions
will prevail through the TAF period. Increasing mid-to-high level
clouds early Saturday morning look to persist through much of the
day. Localized patchy fog is possible near OLM overnight. Overall,
winds look to continue to remain light and variable to calm
overnight (generally southeasterly. The exception being at HQM,
where offshore flow will be enhanced a bit by terrain. Surface flow
will shift southwesterly Saturday morning, with speeds around 4-7 kt
and higher speeds around HQM.

KSEA...VFR conditions prevail through the TAF period. Increasing mid-
to-high level clouds early Saturday morning. Winds light and
variable to calm into the overnight hours (5 kt or less) and
generally southeasterly. Winds will shift southwesterly late
Saturday morning (4-6 kt).

62/29

&&

.MARINE...Broad high pressure over the northeast Pacific will remain
in place through Sunday, continuing the period of light winds and
seas. The next frontal system will move through the waters on
Sunday, bringing a quick round of breezy winds which may require
headlines. Additional systems look to traverse the area waters early
next week, keeping breezy conditions in the forecast, in
particular, on Monday night into Tuesday.

Combined seas 2 to 4 feet through the remainder of today and early
Saturday. Seas will start to gradually build upwards Saturday night
into Sunday, reaching 10 to 13 feet Sunday and remaining in the 8 to
12 ft range through early next week.

62

&&

.HYDROLOGY...Periods of heavy rain next week will force sharp
rises on the Skokomish River in Mason County and the river will be
close to minor flood stage. River flooding is not expected
elsewhere.

&&

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

$$