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000
FXUS66 KSEW 231626
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
926 AM PDT Tue Apr 23 2024

.UPDATE...Forecast on track this morning. Cross cascade gradient
has turned negative and reports from North Bend have east winds
gusting in the 15 to 25 mph range this morning. Low level flow
will not turn onshore for the interior until tonight allowing high
temperatures to rise into the mid 60s to lower 70s. Upper level
trough arriving Wednesday with cooler and wetter weather into the
weekend. Previous discussion below with update aviation and marine
sections. Felton

&&

.SYNOPSIS...High pressure will maintain mild and dry conditions
across the region through Tuesday. From Wednesday through the end
of the week, expect a series of disturbances to bring a return of
clouds and precipitation with temperatures trending closer to
seasonal normals. This pattern will remain through the start of
next week with periodic round of mountain snow and lowland rain.

.SHORT TERM /TODAY THROUGH THURSDAY/...High pressure brings one
more dry and mild day to western WA today. Temperatures will track
a few degrees warmer in the interior with afternoon highs in the
upper 60s to lower 70s. The coast will see 60s too but winds will
be switching to cooler onshore flow this afternoon.

Cooler, cloudier and wetter weather returns for Wednesday as an
upper low tracks through B.C. (with a weak front draped over
western WA). Most of the rainfall will be over the coast and
mountains with some rain shadowing in the central sound. A trough
moves inland on Thursday with more rain and cool weather (highs
in the 50s). Rainfall will be more widespread with much of the
region seeing measurable amounts. 33

.LONG TERM /FRIDAY THROUGH MONDAY/...Troughing over the Pac NW
will keep western WA cool and showery moving into this weekend.
Temperatures will track below average with highs in the 50s. Lows
will be in the 40s. Then, looking further ahead, a deep upper low
will spin offshore as we move into next week. Temperatures
continue to dip below average and we may see lows in the mid to
upper 30s Monday night. Snow levels will lower to around 3000 ft
with a few inches of snow possible at the mountain highway passes.
33

.AVIATION...SW winds aloft as an upper-ridge axis shifts eastward
with troughing upstream. Widespread VFR conditions are expected
through much of the upcoming TAF period. High clouds are pushing
in ahead of the next disturbance entering later on Wednesday.
Surface winds are on the lighter side or calm for many this
morning but should begin to pick up in the afternoon out of the
W/NW between 5- 10 kt as winds push through the Strait of Juan de
Fuca and into the Puget Sound area. Winds will trend more out of
the south on later overnight in response to the aforementioned
system.

.KSEA...VFR throughout the TAF period with high clouds. NNE winds
4 to 8 kt this morning becoming WNW 5 to 10 kt in the afternoon
before a transition to southerly after around 12Z tomorrow
morning.

McMillian/LH

.MARINE...Thermal trough to our south with surface high pressure
well offshore. Generally benign seas today aside from the Central
and Eastern Strait of Juan de Fuca where a SCA is in place through
the overnight. The next disturbance is on tap to arrive early
Wednesday but won`t pack much of a punch. But, the next system will
arrive on Thursday. Winds will likely increase with this system but
the exact details are still uncertain at this time.

4 to 6 feet seas are in the forecast through much of the week.

McMillian/LH

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

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Small Craft Advisory from 2 PM this afternoon to 6 AM PDT
     Wednesday for Central U.S. Waters Strait Of Juan De Fuca-
     East Entrance U.S. Waters Strait Of Juan De Fuca.

&&

$$