188
FXUS66 KSEW 241627
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
927 AM PDT Mon Jun 24 2024

.SYNOPSIS...An upper level ridge will rebuild into the region
today and Tuesday for warmer and drier conditions. Another upper
level trough will produce showers and cooler temperatures across
the area Wednesday and Thursday. A weak upper ridge returns late
in the week for a drying trend, but continued onshore flow will
keep temperatures near normal for the end of June.

&&

.SHORT TERM /TODAY THROUGH WEDNESDAY/...Forecast remains on track
this morning, with no updates required. Expect residual clouds and
showers in the lingering PSCZ to fade away through the morning.

An upper trough centered over the interior of British Columbia
will continue to weaken today as it gradually shifts eastward into
Alberta. This will allow upper ridging to rebuild into Western
Washington today. With the resulting subsidence and drier air
mass, skies will clear out most areas by this afternoon with high
temperatures rebounding to seasonal norms.

Heights continue rise into Tuesday as strong upper ridging
centered over the Desert Southwest builds into the Northern
Rockies. High temperatures across the interior of Western
Washington will warm several degrees with 70s common and few spots
across the Southwest Interior getting into the lower 80s. A
persistent sea breeze will cap temperatures mostly in the 60s
along the immediate coast. Upper ridging shifts eastward on
Wednesday as yet another upper trough moves into the region.
Models continue to generate some respectable QPF with this system.
Showers will spread onshore across the Olympic Peninsula Wednesday
morning then eventually to interior areas by Wednesday evening.
There may be enough instability with this system to generate a
thunderstorm or two near the crest of the North Cascades Wednesday
afternoon. High temperatures will cool 10 or more degrees across
the board.

.LONG TERM /THURSDAY THROUGH SUNDAY/...The upper trough axis
shifts onshore on Thursday giving nearly all of Western Washington
a shot at some measurable precipitation. Meso models are keying
in on a decent convergence zone setting up early Thursday morning.
The trough axis is expected to shift east of the Cascades by
Thursday afternoon. The return of some weak upper ridging is
expected to lead to a drying trend and somewhat warmer
temperatures heading into the end of the week. For Sunday and
beyond, ensembles generally agree that weak upper troughing just
offshore will ensure that onshore flow continues keeping
temperatures from getting much above seasonal normals as June
comes to a close. 27

&&

.AVIATION...Onshore flow will prevail across western WA today.
The flow aloft is westerly, becoming more southerly tonight into
Tuesday as upper level ridging starts to move into the region.
There are a few light showers in weak convergence over the
central and north sound this morning, along with MVFR conditions.
Expect showers to dissipate through the remainder of the morning
and for low clouds to lift and scatter this afternoon for a return
to VFR conditions. 33/14

KSEA...MVFR ceilings this morning with light S winds persisting at
3-7 kt. Clouds will scatter by this afternoon for a return to VFR
conditions. VFR conditions will persist this evening into Tuesday
morning. Winds will flip to the W/NW between 19-22Z and increase
to 7-12 kt before easing again overnight. 33/14

&&

.MARINE...Quick update to seas this morning as latest buoy
observations shows seas persisting at 6-9 ft over the coastal
waters. Expect seas to gradually subside back towards 4-6 ft
tonight into Tuesday and hover within this range for the next
several days.

High pressure over the NE Pacific will maintain relatively calm
conditions and onshore flow through Tuesday. A weak frontal
systems will push inland on Wednesday and again over the weekend.
Strongest winds will be through the Strait of Juan de Fuca through
the period with possible Small Craft Advisories at times throughout
the week. 33/14

&&

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

$$