Area Forecast Discussion
Issued by NWS Seattle/Tacoma, WA

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FXUS66 KSEW 282142
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
242 PM PDT Sat May 28 2022

.SYNOPSIS...An upper trough will move into the region tonight and
Sunday and remain over Western Washington but weaken on Memorial
Day. High pressure will build into the area Tuesday for a couple
of dry and warmer days. A return to unsettled conditions is
expected late next week with another upper trough.

&&

.SHORT TERM /TONIGHT THROUGH TUESDAY/...An upper trough is moving
into the region this afternoon producing a rather wet day across
the southern half of the forecast area. The upper trough will
settle over the area on Sunday for continued showers and cool
temperatures. The trough begins to weaken on Monday with shower
coverage decreasing and mostly ending by evening. With a few
afternoon sunbreaks possible, high temperatures will recover a
handful of degrees but remain below normal. Weak upper ridging
will build into Western Washington on Tuesday for more abundant
sunshine and temperatures nudging upwards to near or a little
above normal.

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...The upper ridge axis
will be overhead on Wednesday for what will likely be the warmest
day of the upcoming week. Many areas across the interior away from
the water will be in the 70s...to near 80 in the Southwest
Interior. The upper ridge shifts eastward and weakens on
Thursday as broad upper troughing sets up over the NE Pacific.
With more onshore flow and gradually lowering heights, Thursday
and Friday will feature more cloud cover, increasing shower
chances (especially over the mountains), and temperatures
gradually cooling to near normal. There is the possibility of more
widespread precipitation early next weekend, but ensemble
solutions vary considerably leaving little confidence in more than
a generic chance of showers forecast. 27


&&

.AVIATION...A Pacific frontal system will move east and inland
through Oregon tonight, with rain through the interior and
Cascades in western WA in a deformation zone. Onshore flow will
increase overnight keeping the air mass moist with MVFR cigs
expected. A convergence zone will likely form over the central
sound Sunday afternoon which may linger through Sunday night. 33

KSEA...Steady rain across the area tonight with lowering ceilings
and MVFR conditions expected. Winds becoming S by 09-12z. Showers
with a convergence zone in the vicinity by 21z Sun and continuing
through Sun night. 33

&&

.MARINE...North to northwest flow will increase tonight as a
Pacific frontal system moves inland - Small Craft Advisories are
in effect. Strong onshore flow will continue through Sunday then
gradually ease on Monday (highest winds through the Strait of Juan
de Fuca). Lighter winds are expected Monday night into Tuesday
with high pressure over the region. The next frontal system will
push inland and weaken over the region on Wednesday. 33

&&

.HYDROLOGY...The daily hydrology discussion has ended until the
start of the next rainy season; it will only be updated as needed
until then.

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Small Craft Advisory from 5 PM this afternoon to 11 AM PDT
     Sunday 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-
     West Entrance U.S. Waters Strait Of Juan De Fuca.

     Small Craft Advisory from 5 PM this afternoon to 5 AM PDT Monday
     for Central U.S. Waters Strait Of Juan De Fuca-East
     Entrance U.S. Waters Strait Of Juan De Fuca.

&&

$$

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