Forecast Discussion for SEW NWS Office
FXUS66 KSEW 261529

Area Forecast Discussion
National Weather Service Seattle WA
829 AM PDT Sun May 26 2019

.SYNOPSIS...Drier and warmer conditions are expected to start today
over much of Western Washington and continue into the week ahead.
Lingering moisture from an upper level low south of the area will
allow for afternoon and evening showers over the Cascades most


.SHORT TERM /TODAY THROUGH TUESDAY/...Wrap around moisture from an
upper low to the south will bring a few showers today and Monday,
mainly to the Cascades. There also might be an isolated
thunderstorm over the Cascades each afternoon and evening where it
will be unstable. A weak upper ridge will move over the area on
Tuesday. It should be a dry day expect for a slight chance of
showers over the mountains in the afternoon.

For today, morning low clouds should burn off but there will be
mid and high clouds coming in from the east so partly sunny is
probably about right. There are currently some showers drifting
west from the Cascades into the metro area but these seem to be
fading as they move off the mountains and it does not look like
they will amount to much. Highs will be near normal today.

There should be less clouds on Monday. The added sunshine will
result in highs warming several degrees with lower to mid 70s for
much of the interior away from the water. Stronger low level
onshore flow should produce morning clouds and afternoon sunshine
on Tuesday with highs cooling 3-6 degrees. Schneider

discussion...Weak upper level ridging will remain the predominant
weather feature for the remainder of the week yielding a generally
dry pattern...however both GFS and ECMWF show occasional hints of
a stray shower here or there due to disturbances associated with
an upper level trough extending into eastern WA. Odds...and thus
POPs...are not terribly favorable for precip...but cannot exactly
leave 0 POPs either. As such...generally silent POPs of less than
10 pct are present. A weak upper level trough looks to move into
the area Friday night...with both models kind of agreeing on
this...and this will see a rise in POPs for near the end of the
forecast period...but models do disagree on how far south the
feature will plunge...and as such have gone with just slight
chance POPs at this time. SMR


.AVIATION...An upper level ridge will build into northern portions
of British Columbia later today. East to northeasterly flow aloft
into tonight with an upper level low located well south of the
area. Surface flow will be light northerly through today becoming
onshore early Monday morning.

Ceilings generally VFR to MVFR currently, though LIFR at KPAE with
nearby vicinity fog at KHQM. Cigs will continue to improve through
the morning with VFR for most by 18z-19z. Mid and high level clouds
will be around into tonight. Light onshore flow late tonight into
early Monday morning may lead to another round of IFR stratus early
Monday, especially across the coast and into the south Sound.

KSEA...Improvement to cigs this morning with MVFR becoming VFR by
18z. Some mid level clouds will be around for the afternoon.
Showers will develop over the Cascades this afternoon but the flow
aloft does not look strong enough to push the showers over the
terminal late this afternoon into this evening. Light onshore flow
will develop late tonight with IFR stratus possible Monday
morning. Northerly winds 7 to 12 knots will become light late this
evening. JD


.MARINE...Light northerly flow will continue through today. Surface
flow will turn onshore early Monday and continue through Tuesday. A
weak surface low will push into the offshore waters later Tuesday
and dissipate into Wednesday.

Small Craft Advisory winds likely for the central and eastern Strait
of Juan de Fuca both Monday and Tuesday evening. The onshore flow
could be strong enough both days for gale force winds. JD


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





NWS SEW Office Area Forecast Discussion