756
FXUS66 KSEW 221003
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
303 AM PDT Sat Jun 22 2024

.SYNOPSIS...A ridge of high pressure aloft will shift east of the
region today. An upper level trough moving onshore over British
Columbia on Sunday will lead to cloudier and cooler conditions
along with a few showers across mainly northern portions of
Western Washington. A upper level ridge will rebuild into the area
on Monday and Tuesday for drier and warmer conditions. Another
trough arrives in the middle of the coming week for cooler
conditions and additional chances for showers.

&&

.SHORT TERM /TODAY THROUGH MONDAY/...Increasing onshore flow ahead
of an approaching upper trough will lead to cooler temps across
the area today. Stratus should remain mostly west of Puget Sound
this morning, but the coast will remain socked in through the day.
Clouds will increase across the interior tonight and a
convergence zone looks likely to develop over Snohomish County for
a few hours on Sunday morning. Cloud cover and spotty precip will
lead to 10 to 15 degrees of cooling Sunday afternoon across much
of the interior lowlands compared to today. The upper trough over
B.C. weakens on Monday with weak upper ridging making some
inroads over Western Washington. This will lead to some clearing
by Monday afternoon with temperatures moderating back to near
normal for late June.

.LONG TERM /TUESDAY THROUGH FRIDAY/...The upper ridge amplifies as
it moves east of the area on Tuesday. This will lead to a dry and
warmer day for interior areas, but increasing onshore flow will
likely to put a lid on temperatures along the coast. Another
upper trough will push onshore Wednesday into early Thursday for
cooler conditions and a decent shot at some showers for much of
Western Washington. There is relatively good model agreement that
weak upper ridging returns by the end of next week for drier
conditions and modestly warmer temperatures. 27

&&

.AVIATION...Upper level ridge to the east combined with upper
level trough offshore giving Western Washington southwesterly flow
aloft through Sunday. Flow aloft increasing tonight into Sunday.
In the lower levels light onshore flow increasing tonight.

Stratus with IFR ceilings along the coast making it as far inland
as the Southern Puget Sound this morning. Stratus retreating back
to the coastline by 18z. Highs clouds over the rest of the area
today. IFR to low end MVFR ceilings continuing along the coast
into Sunday. Ceilings for the interior lowering down to 5000 feet
00z-03z and to MVFR, 2000 to 3000 feet, 06z-09z. MVFR ceilings
continuing through Sunday morning.

KSEA...Just some high clouds today. Ceilings lowering down to
around 5000 feet 03z and to around 2000 feet 06z-09z. MVFR
ceilings continuing through Sunday morning. Light southwesterly
wind increasing to 4 to 8 knots by late morning and to 8 to 12
knots tonight. Felton

&&

.MARINE...Weak front moving through the waters today.
Onshore flow increasing behind the front tonight. Weak high
pressure over the coastal waters with lower pressure inland Sunday
through Tuesday. Another system reaching the waters Wednesday.

Small craft advisory winds in the Central and Eastern Strait of
Juan de Fuca will ease this morning. Winds increasing back up to
small craft advisory for the Central and Eastern Strait late this
afternoon. Small craft advisory winds continuing into Sunday
morning. No advisories or warning for the remainder of the waters.

Seas around 3 feet today building to 7 feet Sunday into Monday
morning as a larger west wave group arrives. Seas then subside
through the remainder of the forecast period. Felton

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Small Craft Advisory until 5 AM PDT early this morning for
     Central U.S. Waters Strait Of Juan De Fuca-East Entrance
     U.S. Waters Strait Of Juan De Fuca.

     Small Craft Advisory from 2 PM this afternoon to 5 AM PDT Sunday
     for Central U.S. Waters Strait Of Juan De Fuca-East
     Entrance U.S. Waters Strait Of Juan De Fuca.

&&

$$