714
FXUS66 KSEW 170952
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
252 AM PDT Fri May 17 2024

.SYNOPSIS...Upper level troughing will continue to remain over
western Washington through the weekend, keeping showery and cooler
conditions around. A weak ridge looks to briefly build in the area
for the start of next week, before troughing returns for more cool
and showery conditions.

&&

.SHORT TERM /TODAY THROUGH SUNDAY/...Recent radar imagery depicts
a weakening convergence zone mainly focused over King/Snohomish
county with some enhanced shower activity. This convergence zone
will continue to weaken into the morning hours as upper level
troughing remains over western Washington. Some lingering showers
will be possible today but any hope for showers will likely be
focused in the Cascades, with mostly dry conditions in the
lowlands. Snow levels remain generally around 3000-3500 feet, with
some light snow showers in the higher peak of the Cascades. Clouds
may break up for some this afternoon, with high temps this
afternoon remaining slightly below average in the low 60s.

Another upper level low with a weak shortwave will then drift
southward into Saturday with another round of showers throughout
majority of the area, with high temps a bit cooler in the upper
50s.

A brief but weak transient ridge will nudge into our area into
Sunday evening for generally dry conditions in the interior and
high temps in the lower 60s.

.LONG TERM /MONDAY THROUGH THURSDAY/...Brief dry conditions will
continue into Monday before another upper level low from British
Columbia moves south into western Washington on Tuesday - with
the return of unsettled weather. Showery and cool weather will
continue yet again into the long term period with temperatures
just slightly below normal.

Mazurkiewicz

&&

.AVIATION...We`re in post-frontal onshore flow this morning with
showers from a convergence zone over King County (where MVFR cigs
are also present). Showers with the convergence zone will push
into the Cascades and diminish by 12z this morning. Elsewhere,
VFR conditions are expected. The low level air mass will remain
moist overnight as onshore flow continues with ceilings near low-
end VFR to MVFR conditions. 33

KSEA...Showers with the convergence zone remaining north of the
terminal this morning. Winds S/SW to 10-14 kt. Cigs becoming VFR
by 12-15Z. 33

&&

.MARINE...High pressure over the NE Pacific will maintain onshore
flow across western WA through the weekend. Strongest winds will
be over the Strait of Juan de Fuca with Small Craft Advisory winds
extending through late tonight. The next frontal system will reach
the region early next week. 33

&&

.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...
WA...None.
PZ...Small Craft Advisory until 11 AM PDT this morning for Admiralty
     Inlet-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-Northern
     Inland Waters Including The San Juan Islands-West Entrance
     U.S. Waters Strait Of Juan De Fuca.

     Small Craft Advisory until 5 AM PDT Saturday for Central U.S.
     Waters Strait Of Juan De Fuca-East Entrance U.S. Waters
     Strait Of Juan De Fuca.

     Small Craft Advisory until 5 AM PDT early this morning for Puget
     Sound and Hood Canal.

&&

$$