179
FXUS66 KSEW 222220
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
320 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/...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. JD

&&

.AVIATION...Mostly VFR across area terminals this afternoon. But,
low clouds look to fill and become more widespread overnight between
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 this afternoon. However, MVFR stratus is
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.

McMillian

&&

.MARINE...Seas around 10-12 ft offshore are maintaining SCA
headlines before they ease into the evening. 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 decreasing 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.

McMillian

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Small Craft Advisory until 6 PM PDT this evening for Coastal
     Waters From Cape Flattery To James Island Out 10 Nm-Coastal
     Waters From James Island To Point Grenville Out 10 Nm-
     Coastal Waters From Point Grenville To Cape Shoalwater Out
     10 Nm-Grays Harbor Bar.

     Small Craft Advisory until 9 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.

&&

$$