266
FXUS66 KSEW 122206
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
306 PM PDT Thu Jun 12 2025

.SYNOPSIS...A weak upper trough will move into Western Washington
today then remain over the area on Friday. This will lead to
cooler temperatures, increased cloud cover, and occasional chances
for mountain showers and coastal drizzle. Upper ridging will
weakly rebuild late in the weekend for a modest warming trend
before another trough approaches the area early in the coming
week.

&&

.SHORT TERM /TONIGHT THROUGH SUNDAY/...A weak upper trough is over
the region today with a few showers along the coast and over the
border in B.C. Onshore flow is keeping temperatures cooler and in
the 50s and 60s. Lows will be cooler overnight and in the 40s.

A deep upper low will spin off SE AK Friday through the weekend.
Western WA is mostly dry with weak ridging and just isolated
light showers in the Cascades. Temperatures are close to average
with highs in the 60s and 70s. Lows will be slightly cooler and in
the 40s. 33

.LONG TERM /MONDAY THROUGH THURSDAY/...A deep upper level low
continues to spin offshore on Monday with ongoing onshore flow
across western WA. The low eventually shifts farther south while
pushing a weak front into the region Monday night or Tuesday for a
chance of showers. The low stalls off southern B.C. midweek then
shifts inland toward the end of the week, with more showers
expected. Temperatures look to track close to average throughout.
33

&&

.AVIATION...An upper level trough will move across the region
today with the flow aloft becoming increasing westerly. Some
lingering mid level clouds continue today with broken to scattered
stratus deck hanging on across the north and the coast. Expect
onshore flow to bring another widespread stratus push overnight with
the Puget Sound terminals again lowering into the MVFR range tonight
09-12z.

KSEA...Expect a mid/high cloud deck to remain at least scattered
through the day. Southerly surface wind will become more west this
afternoon at around 8 kt, before returning southerly tonight. Expect
a return of MVFR stratus tonight after around 10z.

&&

.MARINE...Surface high pressure centered offshore through the end
of the week will move closer to the coastal waters over the weekend.
A weakening front will reach the coastal waters Monday. The small
craft advisory for the coastal waters continues with the steep
conditions. Expect seas to continue to remain around 7 to 9 ft with
the dominant period around 7 or 8 seconds into Friday due to the
persistent northwesterly winds.

Elsewhere, expect diurnally driven pushes of west winds through the
central and eastern Strait of Juan de Fuca each of the next few
nights. Winds will generally be right around 20 kt each night with
some gusts to 25 kt. Will maintain tonight`s advisory for now and
evaluate trends to determine the need for any additional advisories
on subsequent days.

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Small Craft Advisory from 6 PM this evening to 6 AM PDT Friday
     for Central U.S. Waters Strait Of Juan De Fuca-East
     Entrance U.S. Waters Strait Of Juan De Fuca.

     Small Craft Advisory until 6 PM PDT Friday for Coastal Waters
     From Cape Flattery To James Island 10 To 60 Nm-Coastal
     Waters From Cape Flattery To James Island Out 10 Nm-Coastal
     Waters From James Island To Point Grenville 10 To 60 Nm-
     Coastal Waters From James Island To Point Grenville Out 10
     Nm-Coastal Waters From Point Grenville To Cape Shoalwater
     10 To 60 Nm-Coastal Waters From Point Grenville To Cape
     Shoalwater Out 10 Nm.

&&

$$