412
FXUS66 KSEW 141022
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
322 AM PDT Fri Mar 14 2025

.SYNOPSIS...Additional systems entering tonight through Monday
will bring lowland rain, steady mountain snowfall, and
occasionally breezy conditions. Brief upper level ridging will
provide a break through early Wednesday before active weather
returns later in the week.

&&

.SHORT TERM /TODAY THROUGH SUNDAY/...A trough axis will move over
western Washington this morning, bringing scattered showers to
the region. Recent radar imagery early this morning shows some
weak convective showers moving onshore, moving northeastward
through the area. These convective showers are pretty weak in
terms in overall instability, and will generally weaken as they
move through the interior. Snow levels early this morning around
1000 to 1500 feet could result in a rain/snow mix on some of the
higher hills across the area, but with these showers weakening,
confidence is fairly low. No significant accumulation is expected
with these.

Overall, shower activity will generally weaken throughout this
afternoon before another system slides into the region this
evening, bringing another round of widespread lowland rain,
mountain snow, and breezy conditions at times into the first half
of next week.

Snowfall in the mountains will continue through the weekend and
into the first half of next week, being a somewhat continuous
event. Even though snowfall is fairly spread out during this
time, higher snowfall rates Saturday into Sunday will raise
accumulations in the Cascades, and therefore, have issued a Winter
Storm Warning.

High temperatures across the interior will remain in the upper
40s to lower 50s for much of the forecast period.

.LONG TERM /MONDAY THROUGH THURSDAY/...Unsettled conditions
continue through Tuesday, before a brief break in precipitation
arrives midweek. Alas, this break will be short-lived as the
active weather pattern continues, with additional systems entering
the area starting on Thursday with cool and wet conditions.

28

&&

.AVIATION...Westerly flow aloft continues over the region today with
a splitting system moving onshore later today mainly south of the
area. A secondary system will move onshore over Western Washington
late tonight. Areas of MVFR in scattered showers will lift to
primarily VFR ceilings from mid-morning through the afternoon.
Ceilings will lower to MVFR in increasing rain along the coast this
evening with said conditions spreading inland overnight.

KSEA...Expecting primarily VFR ceilings today as a system moves
onshore south of the area. Ceilings will lower to at or below 3000
feet 06Z-09Z tonight as another round of precipitation moves into
the area. Surface winds E/SE 5 to 8 knots shifting northeasterly
this afternoon.   27

&&

.MARINE...A surface low over the Oregon offshore waters will
gradually weaken as it moves into the Washington coastal waters late
tonight. This will produce small craft advisory conditions over the
coastal waters today. Onshore flow will develop as the low moves
onshore on Saturday. Weak troughing will remain over the waters into
Monday before a surface ridge builds across the waters Monday night
into Tuesday. Another front will approach the coastal waters around
the middle of the coming week.

Coastal seas at or above 10 feet will continue through the weekend
before subsiding early next week.   27

&&

.HYDROLOGY...Heavy precipitation in the southern Olympics this
weekend will result in rises on the Skokomish River. Current
projections bring the Skokomish River into Minor flood stage
Sunday. A hydrologic outlook remains in effect through Monday
morning. While other rivers will experience rising water levels,
river flooding is not expected elsewhere over the next 7 days.

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...Winter Storm Warning from 5 AM Saturday to 11 AM PDT Sunday for
     West Slopes North Cascades and Passes-West Slopes North
     Central Cascades and Passes-West Slopes South Central
     Cascades and Passes.

PZ...Small Craft Advisory until 5 PM PDT this afternoon 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.

&&

$$