056
FXUS66 KSEW 071035
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
335 AM PDT Fri Jun 7 2024

.SYNOPSIS...Upper level ridge over Western Washington today and
tonight will shift east Saturday. Weak upper level trough moving
through Sunday followed by a weak ridge Monday. Zonal flow aloft
Tuesday through Thursday with weak systems moving by to the north
at times.

&&

.SHORT TERM /TODAY THROUGH SUNDAY/...Satellite imagery shows high
amplitude upper level ridge in the Eastern Pacific early this
morning. Mostly clear skies over Western Washington. Temperatures
at 3 am/10z were in the mid 40s to mid 50s.

Upper level ridge over Western Washington today. While the
gradient through the Strait of Juan de Fuca goes negative, the
cross Cascade gradient will remain positive. Winds at 850 mb
don`t turn easterly for any significant period of time. With the
low level flow not turning offshore this will keep high
temperatures about 5 to 10 degrees warmer than Thursday, in the
70s to lower 80s.

Upper level ridge axis over Western Washington tonight with clear
skies. Lows in the upper 40s to mid 50s.

Upper level ridge axis shifting into Eastern Washington Saturday
afternoon. Low level flow turning onshore in the afternoon with
temperatures aloft beginning to cool. Morning low temperatures
Saturday 5 degrees or so warmer than this morning so even with
less day time heating Saturday highs will end up similar to today
over the interior with another round of 70s to lower 80s.
Different story along the coast where the increasing onshore flow
will cool high temperatures back down into the 60s.

Weak slow moving upper level trough offshore reaching the
coastline around 12z Sunday making it to the Cascades by 00z
Monday. Not much moisture with this feature. Increasing onshore
flow will give the area some cloud cover Saturday night into
Sunday. With the air mass slightly unstable there is a chance for
showers in the Cascades Sunday. Lows Saturday night in the upper
40s to mid 50s. Highs on Sunday cooler with mid 60s to mid 70s for
the interior and lower to mid 60s for the coast.

.LONG TERM /MONDAY THROUGH THURSDAY/...Extended models showing
good run to run consistency this morning with a weak upper level
ridge moving through Western Washington Monday ahead of another
weak upper level trough Tuesday. The trough will give the coast
and Olympics a chance for light showers or drizzle especially in
the morning. Zonal flow aloft Wednesday and Thursday with
additional weak shortwaves moving by to the north keeping a chance
of showers in the mountains and the north coast. The shortwave
Thursday could be strong enough to produce some light showers over
the northern portion of the interior.

Highs in the interior in the mid 60s to mid 70s Monday cooling to
the 60s and low 70s Tuesday, 60s Wednesday and lower to mid 60s
Thursday. Highs along the coast in the lower 60s through the
period. Felton

&&

.AVIATION...High pressure over the region for dry and stable
weather. The flow aloft is N to NW with northerly winds near the
surface. VFR conditions will prevail.

KSEA...VFR today with N winds increasing to 10-15 kt this
afternoon. 33

&&

.MARINE...Northerly flow prevails over the waters today with high
pressure over the region. High pressure will shift east of the
Cascades on Saturday with increasing onshore flow Saturday night -
Small Craft Advisory winds are likely through the Strait of Juan
de Fuca. High pressure over the NE Pacific will maintain onshore
flow through Sunday. Another front will cross western WA Monday
night. 33

&&

.HYDROLOGY...Just a reminder that even with the warmer
temperatures today and Saturday, water temperatures remain very
cold. Here is a sampling around the area, Skykomish River 48
degrees, Tolt River 49 degrees, Skagit River 45 to 47 degrees. In
the metro area Lake Washington 58 degrees, Lake Sammamish 62
degrees and Puget Sound 52 degrees. Let`s be safe around the water
the next few days. Felton

&&

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

$$