625
FXUS66 KSEW 072148
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
248 PM PDT Mon Apr 7 2025

.SYNOPSIS...More rain and mountain snow through Tuesday with a
trough over the region. Weak upper level ridge trying to build
over the area Wednesday. The ridge will shift east Wednesday night
into Thursday allowing another front to reach the area Thursday
night. Cool upper level trough over Western Washington Friday and
Saturday with an upper level ridge building Sunday.

&&

.SHORT TERM /TONIGHT THROUGH THURSDAY/...There is broad troughing
over the Pac NW with a parent low spinning offshore near the Gulf
of AK. Across western WA, we`re under moist S/SW flow with
batches of rain moving in and out. The air mass is slightly
unstable and there`s a chance of thunderstorms over the region
too. Snow levels will lower tonight, around 3500-4000 ft, and the
volcanoes may see periods of heavy snow. A Winter Storm Warning is
in effect with heaviest amounts over Mount Baker and Mount
Rainier (up to a foot of snow).

Wet weather continues into Tuesday with more rain and mountain
snow. Showers are enhanced with a passing trough axis due to cross
western WA during the afternoon. Heavy snow is still expected at
Mount Baker, Mount Rainier and White Pass. Snoqualmie will see a
rain/snow mix with around 4-6" at Stevens Pass. By Tuesday night,
we`ll be in post-frontal flow with showers and a convergence zone
aimed at Snohomish and Skagit counties.

A weak ridge will bring drier weather moving into Wednesday. The
air mass will be warmer with temps in the upper 50s to lower 60s.
The ridge holds on going forward to Thursday, keeping part of the
day dry. Rain returns late Thursday afternoon and evening as the
ridge shifts east and a front moves in from the Pacific. 33

.LONG TERM /FRIDAY THROUGH MONDAY/...A trough over the West will
keep rain chances going Friday through the weekend. Temperatures
will be cooler with morning lows in the 30s (beginning Saturday
morning). We`ll see light snow in the mountains as well. High
pressure brings drier weather later Sunday and into early next
week for a break in the weather. 33

&&

.AVIATION...Moist southwesterly flow aloft as upper level
troughing continues to bring showers to western Washington. A
mixed bag of conditions out there this afternoon from VFR to IFR
as heavier batches of showers move through. On and off shower
activity will continue into Tuesday as the aforementioned upper
level troughing moves onshore. Can expect lower conditions
(MVFR/IFR) at times throughout most of the terminals through the
overnight hours due to showers and low level moisture keeping
ceilings low. SW winds look to become breezy around 22z-02z, with
possible gusts up to 20 to 25 kts across the area.

KSEA...MVFR to VFR conditions out there this afternoon as batches
of showers continuously move through the terminal. Showers will
continue to move through into the evening, which will keep
conditions hovering around MVFR/VFR. Breezy S/SW winds around 12
to 16 knots this afternoon accompanied by gusts possible up 20 to
25 knots. Winds will slightly ease overnight but will remain
around 8 to 12 knots. Conditions look to remain at MVFR Tuesday
morning (15z-19z) as more showers move through the area, with
another round of breezy southerly winds.

Mazurkiewicz

&&

.MARINE...A frontal system moving through the area waters will
keep winds slightly elevated over the coastal waters and the
interior waters. A small craft advisory remains in effect for the
coastal waters for elevated seas and winds, along with the Central
and Eastern Strait for a push of westerly winds ranging from
15-25 kts. Another disturbance will push through the waters on
Tuesday and will bring breezy southerlies across the waters. A
brief break from the weather through Wednesday and Thursday before
another system approaches the area near the end of the week.

Combined seas around 9 to 11 feet will generally remain through
Tuesday. Seas look to subside to around 5 to 7 feet by midweek,
before gradually building back up to 10 feet by the end of the
week.

Mazurkiewicz

&&

.HYDROLOGY...A Flood Watch is effect for the Skokomish River in
Mason County. This is due to the river already running high with
an additional 2 to 2.5 inches of rain along the south slopes of
the Olympics in the next 36 hours. The current forecast has the
river cresting just a few inches below flood stage late Tuesday
night. If the Skokomish River does reach flood stage, it will not
remain over flood stage long with the watch ending Wednesday
morning.

No river flooding on the remainder of the rivers in the next 7
days.

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...Winter Storm Warning from 5 PM this afternoon to 5 PM PDT
     Tuesday for Cascades of Pierce and Lewis Counties-Cascades
     of Whatcom and Skagit Counties.

     Flood Watch from Tuesday afternoon through Wednesday morning for
     Foothills of the Western and Southern Olympic Peninsula-
     Middle Chehalis River Valley-Olympia and Southern Puget
     Sound-Olympics-Southern Hood Canal-Willapa and Black Hills.

PZ...Small Craft Advisory until 9 PM PDT this evening for Central
     U.S. Waters Strait Of Juan De Fuca-East Entrance U.S.
     Waters Strait Of Juan De Fuca.

     Small Craft Advisory until 11 AM PDT Tuesday for Coastal Waters
     From Cape Flattery To James Island 10 To 60 Nm-Coastal
     Waters From Cape Flattery To James Island Out 10 Nm-Coastal
     Waters From James Island To Point Grenville 10 To 60 Nm-
     Coastal Waters From James Island To Point Grenville Out 10
     Nm-Coastal Waters From Point Grenville To Cape Shoalwater
     10 To 60 Nm-Coastal Waters From Point Grenville To Cape
     Shoalwater Out 10 Nm.

&&

$$