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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS66 KSEW 092146
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
246 PM PDT Fri Jun 9 2023

.SYNOPSIS...
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Cool and showery conditions are expected across
western Washington into the first half of Saturday. Dry conditions
and temperatures warming to above normal through Monday.
Conditions will gradually cool back toward normal through the end
of next week.
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&&

.SHORT TERM /TONIGHT THROUGH MONDAY/...
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Rain showers continue to
spread northwest across western Washington this afternoon as a weak
and broad upper level low slides north around a blocking ridge over
central Canada. Impacts from this rain will largely be beneficial
due to the recent dry conditions, though roads will be slick and we
will continue to monitor the area burn scars for flood hazards.

The area will be situated between a reinforcing trough along the
California coast and the blocking ridge over south central Canada
on Saturday before ridging over the eastern Pacific noses into
the region Sunday and Monday. This evolution will result in
precipitation gradually diminishing from southwest to northeast
through the day on Saturday and then a quick warm up Sunday and
Monday. Temperatures by Monday will reach back into the 80s again
for much of the interior lowlands and are likely to bring back a
few areas of Moderate/Orange HeatRisk.

.LONG TERM /TUESDAY THROUGH FRIDAY/...The warm conditions Monday
will be short-lived as a progressive shortwave moves overtop of the
eastern Pacific ridge. Impacts from the wave will largely be felt
north and east of the area with the main sensible weather effect for
Washington being a weak and dry front resulting in a cooling trend
through the remainder of the work week.

Looking out a bit further, there are some hints of additional
troughing late next week that could bring some cooler air and
additional precipitation to the region. This is also reflected in
the CPC 6-10 day outlook. -Wolcott-
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&&

.AVIATION...
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Light flow aloft as an upper-low meanders across the
region. Light onshore flow is also present in the lower levels. A
mixed bag of VFR to MVFR/IFR is currently observed. For tonight, any
lingering VFR cigs will transition to all MVFR/IFR into the early
morning hours on Saturday. Isolated instances of low visibility are
possible under heavier precipitation as showers persist overnight.
Low stratus is in the forecast into Saturday as well but conditions
should gradually improve late in the day as shower activity
decreases.

KSEA...MVFR ceilings are in the forecast tonight into Saturday
morning. IFR cigs are also possible but of a much lesser chance (20-
25 percent). Shower activity is likely to persist during this time
with some dry time in between. Southwest winds 3 to 8 knots through
much of the upcoming TAF period.

McMillian
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&&

.MARINE...
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Surface high pressure over the northeast Pacific
with lower pressure inland into the beginning of the week. The high
will strengthen Sunday into Monday and possibly bring headline winds
for the outer coastal waters. A weak upper level system will
continue to bring rain and showers mostly to the inland waters
through Saturday.

An additional SCA has been issued this evening for westerly winds
through the central section of Strait of Juan de Fuca. They appear
to be borderline with gusts around advisory criteria being the main
reason for the issuance. Winds are to decrease late overnight into
early Saturday morning. Seas generally 2 to 4 feet tonight through
Saturday before increasing to 6 to 8 feet Saturday night into
Sunday and remain elevated through the beginning of next week.

McMillian
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&&

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

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
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WA...None.
PZ...Small Craft Advisory until 2 AM PDT Saturday for Central U.S.
     Waters Strait Of Juan De Fuca.
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&&

$$