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000
FXUS66 KSEW 111100
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
400 AM PDT Thu Apr 11 2024

.SYNOPSIS...A front will enter the area on Thursday accompanied
by widespread precipitation. Afterwards, dry conditions are to
follow with weak high pressure in place over the weekend. The
next disturbance will usher a return of rain, mountain snow, and
cooler conditions into next week.


&&

.SHORT TERM /TODAY THROUGH SATURDAY/...Latest satellite imagery
indicates increasing cloud coverage across the region. This cloud
shield is associated with an occluded surface low over the NE
Pacific. Its associated front will enter and weaken across
western Washington later today with a shot of widespread rain and
some mountain snow for elevations above 4,000 ft. 0.50-1.00" of
rainfall is expected along the coast and surrounding areas.
Locations within the interior will see 0.10-0.25" with locally
higher amounts in the foothills and higher elevations. High
temperatures won`t stray far from average with highs in the 50s.
Any lingering precipitation will taper off into the nighttime with
overnight lows falling into the 40s.

Guidance has the upper-level pattern progressing into the weekend.
The upper-trough associated with the aforementioned frontal
system will sink southward and position off the coast of CA. We`ll
see weak ridging nose into western WA during this time and persist
into Saturday. Conditions are forecasted to dry out and warm up
with widespread upper 50s and 60s at play.

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...Weak ridging will stick
around for one more day on Sunday. But, onshore flow will increase
as relatively cooler temps return. Then, models are in agreement
regarding the return of upper-level troughing on Monday. The dry
spell will come to an end with PoPs reintroducing themselves
during this time. Snow levels will also lower to 2,000 ft with a
few inches of snow at the highway passes. Temps will track cooler
than average with lows in the 30s to lower 40s. Temps could fall
near-freezing Tuesday morning around the south sound. Going
forward, ensembles are hinting at drier and warmer weather
towards midweek with upper-level ridging looming offshore.

McMillian

&&

.AVIATION...Slowly moving front is largely remaining in place
offshore this morning. VFR conditions continue area wide
with variable high clouds continuing to be in place. Ceilings will
gradually lower into MVFR category toward 14z with leading rain
reaching KUIL/KHQM. Expect lower conditions to very slowly spread
inland to reach the Puget Sound terminals toward 00z, but with the
front falling apart confidence in the timing and height of ceilings
remains low.

KSEA...VFR with high clouds this evening. Ceilings lowering
through the day, especially after daybreak, but this trend will be
very gradual. With the front weakening, less than 20% chance of MVFR
ceilings through 00z, but expect lower clouds to eventually arrive
at the terminal toward 03-05z in very light rain. Light northerly
surface winds this morning, flipping to light southerly around 12z.
Southerly surface winds increase closer to 10 kt late afternoon with
the front, before again becoming light after 06z Friday.    Cullen


&&

.MARINE...A weak front remains placed over the outer coastal
waters this morning and will slowly shift inland as it falls
apart through the day. Expects winds with the front to generally
remain in the 15-20 kt range with a low (20-35%) chance of sustained
advisory strength winds. Could see a few gusts immediately with
frontal passage, but not expecting these to be prolonged or
widespread to warrant an advisory.

Seas will remain around 5 to 7 ft today through Friday. High
pressure rebuilds over the waters, with winds expected (greater than
80% chance) of remaining below advisory thresholds through Saturday.
Seas will build into the 8 to 11 ft range over the coastal waters as
a shorter period northwest wave group arrives by the start of next
week, with conditions remaining somewhat steep. Winds also increase
around Monday with the arrival of a stronger frontal system.
Cullen


&&

.HYDROLOGY...No river flooding is expected through the next seven
days.


&&

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

$$