873
FXUS66 KSEW 230409
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
909 PM PDT Wed May 22 2024

.SYNOPSIS...Weak high pressure will build aloft for drier and
somewhat warmer conditions on Thursday. Another upper trough will
move across Washington Friday into Saturday for cooler and
unsettled conditions. Ridging will begin to build into the
interior West next week for warming temperatures, but continued
troughing offshore will allow for chance of precipitation.

&&

.SHORT TERM /TONIGHT THROUGH SATURDAY/...Clouds and showers
continue to diminish in coverage this evening as the occluded low
across eastern Washington weakens. No major changes to the
forecast this evening.

An upper low located across eastern Washington will continue to
move southeastward tonight allowing for lingering showers over the
Cascades to dissipate during this period. Weak high pressure
aloft will briefly build in Thursday for slightly warming
temperatures, generally drier conditions, and some sunshine.
Troughing will develop Friday into Saturday for a return of
unsettled conditions. Rain showers will increase into Friday
morning for the coast, and then slowly move eastward through the
day, but expected to remain generally light. Weak convergence may
occur Friday night into early Saturday across central Puget Sound.
Otherwise, temperatures will generally range in the upper 50s to
low 60s Friday and Saturday.

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...Ridging will begin to
nudge into western Washington later Sunday into Monday, allowing
for warming temperatures into next week. However, continued
troughing offshore will allow for southwesterly flow aloft,
leading to continued precipitation chances, mainly for the Olympic
Peninsula and areas near the border during this period.
Uncertainty increases in ensembles Tuesday in regards to the
extent ridging builds into western Washington with troughing
offshore. However, at least some troughing is expected to move
across the Pacific Northwest later Tuesday into Wednesday,
increasing precipitation potential. Normal to slightly above
normal temperatures Monday into Tuesday, with perhaps some
cooling for Wednesday.

Davis/JD

&&

.AVIATION...Mostly VFR this evening, with stratus hanging on at
HQM still. Low clouds look to fill and become more widespread
overnight by 08-12z Thursday for most interior terminals. For
these airfields, confidence is leaning towards MVFR cigs but can`t
rule out a 20-30% chance of IFR for locations such as KPWT.
Northerly winds 5-10 kt will switch out of the south to southwest
this evening around 03- 06z. Any lingering low clouds should
scatter around 18-20Z Thursday back to VFR criteria.

KSEA...VFR conditions currently this evening. However, MVFR
CIGS are expected to redevelop overnight around 08-10z Thursday.
These cigs are to hang around before scattering back to VFR
conditions by 18-20Z Thursday. Northerly winds look to switch out
of the SSW by 04-06Z tonight between 8-12 kt and remain into
Thursday.

Davis/McMillian

&&

.MARINE...Seas around 8 to 10 ft offshore are maintaining SCA
headlines before they ease into the early overnight. Seas have
dropped below 10 feet over the inner coastal waters and at Gray`s
Harbor Bar. Afterwards, conditions should trend more benign into
the remainder of the night and Thursday. However, the next frontal
system is expected to pass through area waters on Friday. This
will likely bring another round of elevated seas and breezy winds.

Seas still hovering around 10 ft over the offshore coastal zones
but are expected to decrease to 6 to 8 ft overnight before
settling around 3 to 5 for both Thursday and during the day on
Friday. Then, a NW wave train looks to arrive Friday night helping
to increase seas to around 8-10 ft through early Saturday
morning.

Davis/McMillian

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Small Craft Advisory until 11 PM PDT this evening for Coastal
     Waters From Cape Flattery To James Island 10 To 60 Nm-
     Coastal Waters From James Island To Point Grenville 10 To
     60 Nm-Coastal Waters From Point Grenville To Cape
     Shoalwater 10 To 60 Nm.

&&

$$