414
FXUS66 KSEW 051734
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
1034 AM PDT Sun May 5 2024

.SYNOPSIS...Cool and unsettled conditions continue across the
region early this week. A shift in the pattern toward midweek with
bring about dry conditions and steadily warming temperatures
through the second half of the week.

&&

.SHORT TERM /TODAY THROUGH TUESDAY/...A damp and dreary morning
across western Washington with a few bands of showers across the
Puget Sound lowlands, with areas of mist and light drizzle,
otherwise. Rain coverage is expected to increase later in the day
as stronger onshore flow develops with stronger diffluent flow
aloft ahead of the next incoming upper-level trough. Expect
primarily rain through the interior, though some light snow will
be possible above around 4500 feet and especially in the higher
Cascade elevations.

The aforementioned stronger upper-level trough will further move
into the region on Monday. As cooler air aloft pushes into the
region, steepening lapse rates will increase the potential for
isolated thunderstorms through the day on Monday. Strong onshore
flow will develop with a Puget Sound Convergence Zone likely to
develop into the afternoon and evening. While snow levels will dip
a bit closer to the Cascade passes, the most significant threat
for strong showers will be under the PSCZ, especially if it`s able
to push into the mountains.

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...Ensemble guidance
continues to depict high confidence in a shift to a much warmer
pattern through the second half of the week as a strong ridge
builds over the western U.S. starting around midweek. Still some
variations evident in the clusters of ensemble members with
respect to where the ridge axis sets up and just how strong it is,
but confidence is high in seeing temperatures climb to at least
10 to 15 degrees above normal by the late stages of the week for
much of the lowlands. Current forecast from the NBM suggest a run
into the lower to mid 80s is possible for the warmest spots
Saturday. While the precise temperature forecast will fluctuate a
bit in the coming days, it`s worth noting that this will be a
significant warm up and coupled with the calendar turning to May,
many folks may be out around area water. Keep in mind that local
waters are still quite cool and be sure to adhere to safety
practices if you`re out in or around the water later this week.

Davis/Cullen

&&

.AVIATION...A mixed bag of restrictions this morning across the
western Washington terminals with LIFR,IFR, MVFR, and VFR
restrictions-with LIFR and IFR being mostly around the Puget Sound
terminals, though some improvement towards MVFR does appear to be
occuring. Upper-level low over Southeast Oregon moving east
today. Frontal system spinning out of upper-level low in the Gulf
of Alaska moving into the area tonight and Monday morning. Light
and variable flow aloft becoming westerly this afternoon. Flow
aloft increasing tonight into Monday. In the lower levels onshore
gradients into Monday.

Lingering LIFR and IFR at the Puget Sound terminals should
gradually trend towards MVFR ceilings over the remainder of the
area except for VFR ceilings near the Canadian border and at BLI
and CLM. Slow improvement late morning into the afternoon hours
with MVFR ceilings mostly locations after 21z.

KSEA...CIGs have lifted to MVFR, where they should generally
remain into Monday morning (60% confidence for MVFR or lower
through tonight). Southerly winds 6 to 10 kt increasing to 10 to
15 kt with gusts 20 to 25 kt after 21z.

Davis/Felton

&&

.MARINE...A frontal system will move across the waters tonight
into Monday morning. High pressure will build back over the area
Monday night and Tuesday with the ridge remaining in place
Wednesday and Thursday.

Small craft advisory winds continuing in the Central Strait of
Juan de Fuca through at least Monday. Small craft advisory winds
for the Eastern Strait today into tonight. Winds in the Eastern
Strait easing late tonight then increasing again back up to small
craft advisory speeds Monday afternoon. Small craft advisory
winds in the Puget Sound and Hood Canal beginning this afternoon
and continuing through Monday. Continue to monitor the potential
for wind to reach advisory-level across the Northern Inland
Waters and over the coastal waters.

Seas building to near 10 feet Monday night and remaining near 10
feet Tuesday.

Davis/Felton

&&

.HYDROLOGY...No river flooding is expected through the next seven days.

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Small Craft Advisory until 5 AM PDT Tuesday for Central U.S.
     Waters Strait Of Juan De Fuca.

     Small Craft Advisory until 2 AM PDT Monday for East Entrance
     U.S. Waters Strait Of Juan De Fuca.

     Small Craft Advisory from 2 PM this afternoon to 6 PM PDT Monday
     for Puget Sound and Hood Canal.

&&

$$