692
FXUS66 KSEW 100258
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
758 PM PDT Sun Jun 9 2024

.SYNOPSIS...Brief upper-ridging will rebound on Monday but only
to be replaced by weak troughing and shower activity on Tuesday.
Mostly zonal flow aloft afterwards with near-normal temperatures
however, cooler and wetter weather looks to return by the weekend.

&&

.SHORT TERM /TONIGHT THROUGH WEDNESDAY/...No significant changes
were made to the forecast this evening. The previous discussion
can be found below along with updated aviation and marine
sections:

As mentioned, a transient ridge looks to build into the region
tonight as upper- troughing shifts into the Inland Northwest.
Mostly dry conditions are expected but onshore flow looks to
strengthen. With that, widespread marine stratus is expected to
develop across W WA overnight into early Monday. Low temperatures
are to range mid 40s to lower 50s around seasonal after a day of
above average temperatures.

Dry conditions are favorable for Monday with weak ridging in the
500 mb levels but upper-troughing will return Monday night into
Tuesday along with shower chances. Areas with the best chance for
wet weather are favored mostly along the coast, northern interior
and higher elevations. Temperatures are expected to cool also, as
forecast highs on Monday of low to mid 70s across the interior
will fall to the mid to upper 60s on Tuesday. Low temperatures
are to be in the mid 40s to lower 50s for both nights.

We`ll see zonal flow aloft on Wednesday throughout the region.
Any lingering showers are expected to dry out but marine stratus
will remain during the morning before burning off by the
afternoon. Pleasant conditions are in the offing with seasonal
temperatures.

.LONG TERM /THURSDAY THROUGH SUNDAY/...Guidance is keying in on
weak ridging returning on Thursday with a slight bump up in
temperatures. But, a trough will swing out of the Gulf of Alaska
and into the region on Friday and influence conditions into the
weekend. Here we`ll see another period of below-normal
temperatures and chances for showers across the region.

McMillian

&&

.AVIATION...A weak upper level trough will continue to exit the
region, moving into eastern Washington tonight. Zonal flow will then
persist tonight into Monday. Stratus continues to linger over the
coast and the lowlands of the western Olympic Peninsula, keeping
MVFR conditions in place there. VFR elsewhere this evening and into
tonight. Increasing low level onshore flow tonight will yield
another round of stratus pushing into the interior by early Monday
morning (most likely between 09-12Z for interior terminals). Extent
of stratus looks to be more widespread than this morning and will
likely result in a few hours of MVFR to IFR conditions. A rebound to
VFR for majority of terminals likely by 18Z as stratus scatters.
Coastal sites may take a bit longer, if they break out at all.

KSEA...VFR this evening and tonight with S/SW winds 5-10kt. Low
clouds and MVFR conditions, along with light/variable wind,
overnight toward 12Z Mon. Stratus should scatter out by 18Z with VFR
conditions returning.

14/18

&&

.MARINE...High pressure will remain situated over the northeastern
Pacific through Monday for periods of northerly winds over the
coast and westerlies through the Strait of Juan de Fuca. Another
strong push of westerlies is expected down the strait tonight- where
a Gale Warning remains in effect. Seas throughout the coastal waters
have eased below 10 ft at the time of this writing and as such, the
SCA issued this afternoon for this area will be allowed to expire.
Seas will gradually continue to subside tonight getting to 4-6 ft
for Monday. A frontal system is expected to cross the area waters
Tuesday, bringing seas back to 10-12 ft in the coastal waters. High
pressure will then build back into the region Tuesday night into
Wednesday. Another front looks to traverse the area waters late in
the week.

14/18

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Small Craft Advisory until 8 PM PDT this evening 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-Grays Harbor Bar.

     Gale Warning until 5 AM PDT Monday for Central U.S. Waters
     Strait Of Juan De Fuca-East Entrance U.S. Waters Strait Of
     Juan De Fuca.

&&

$$