462
FXUS66 KSEW 242255
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
255 PM PST Sun Nov 24 2024

.SYNOPSIS...An upper-low will continue to churn off the PNW coast
for the start of the new week with active weather continuing. Drier
conditions expected towards the Thanksgiving holiday as an upper
level ridge brings calm weather but cooler temperatures.


&&

.SHORT TERM /TONIGHT THROUGH WEDNESDAY/...Activity slowing down
somewhat over W WA this afternoon...but looking into far SW WA and
NW OR, this may be more of an instance of reloading as showers there
look to be on a northeasterly trajectory. Radar trends suggest that
by the time these showers make their way into the CWA, they will
likely be more of a concern for the Cascades and not so much for
remaining areas. That said, there is still some scattered activity
over portions of the Olympic Peninsula as well as along the east
Sound...but these echoes are pretty light with not much in the way
of rainfall expected.

Model solutions remain consistent for the near term with both
deterministic and ensemble members slowly pulling aforementioned low
southward throughout the day today. This will allow the system to
draw moisture up into W WA to continue to fuel the shower risk today
and Monday. Once the low starts to make its way inland, models
remain in agreement that its storm track will take it more into
central or southern OR, thus taking its moisture with it. While this
may still allow for some showers to persist over portions of the
CWA, this will ultimately allow for lowering PoPs and drying
conditions for Tuesday. Upper level ridging will nudge into W WA
Wednesday initiating an overall dry period, however models continue
to agree that this feature will not scour moisture out immediately,
allowing for some low-end PoPs to linger over much of the area.
Terrain coupled with this moisture will lead to better PoPs over the
Cascades.

High temps for the entirety of the short term lingering in the mid
40s to around 50 with overnight lows in the upper 30s to lower 40s.

18

.LONG TERM /THURSDAY THROUGH SUNDAY/...Long term forecast, much like
the short term, remains pretty consistent with upper level ridging
dominating the weather pattern at least into Friday. Starting to see
some deviations in the Friday/Saturday time frame as deterministic
GFS wants to break down the ridge early in favor of an incoming
frontal system. Neither ECMWF nor majority of ensemble members are
indicating such...so while NBM is busy trying to squeeze PoPs from a
stone, the best likelihood still sides with dry conditions
persisting. GFS recalibrates itself with ridging resuming for the
closing frame of the long term with dry conditions Saturday and
Sunday.

Daytime highs slip a little, but not much...ranging in the mid to
upper 40s while overnight lows do end up getting colder in the lower
to mid 30s.

18

&&

.AVIATION...Upper level low slowly drifting south offshore with
moist southwesterly flow aloft over the area. Light easterly
gradients in the lower levels.

MVFR ceilings continuing into Monday afternoon. Possible IFR
ceilings over the Kitsap Peninsula with a little upslope flow into
the Olympics.

KSEA...MVFR ceilings through Monday afternoon. Easterly winds 4
to 8 knots becoming northeast after 09z. Felton

&&

.MARINE...A 1004 millibar surface low west of Cape
Disappointment will continue to weaken as it drifts east tonight
and Monday. The low will dissipate off the Oregon coast Monday
night. High pressure will build over the waters Tuesday and remain
over the waters through Friday. Winds remaining below small craft
advisory through late week.

&&

.HYDROLOGY...The Skokomish River will remain near flood stage
into Monday with light precipitation overnight. The river will
slowly recede beginning Monday night dropping below flood stage
Monday night into Tuesday. The river will remain below flood stage
the remainder of the week.

For the rest of the rivers no flooding is expected with no
hydrologically significant precipitation in the forecast. Felton

&&

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

&&

$$