Mt. Baker

000
FXUS66 KSEW 111000
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
300 AM PDT Fri Sep 11 2026

.SYNOPSIS...
Troughing developing over the area will continue into this 
weekend, bringing unsettled conditions and cooler temperatures 
to the region. Ridging looks to rebuild through the first half 
of next week for a slow warming trend. 

&&

.SHORT TERM /TODAY THROUGH SUNDAY/...
An upper level trough over the region will continue to bring 
onshore flow, cooler temperatures, and unsettled weather to 
western Washington over the next couple of days. It'll deepen
today as its associated upper-low forms off the BC coast and 
positions offshore by this evening. As a result, light shower 
activity is possible over the Olympic Peninsula tonight but 
conditions are to remain mostly dry across the area. Highs today
will top out in the 60s to near 70 F with overnight lows in the
50s.

The upper-low will traverse across the region on Saturday,
bringing widespread rain, showers and a 15-20% chance for 
thunderstorms. The highest probability for lightning is over the
Olympics and southwest interior according to the NBM. It'll hang
around through Sunday with continued precipitation chances but
the thunderstorm threat will diminish with probabilities less
than 10%. High temperatures ranging between the 60s to near 70 F
and lows mainly in the 50s for both Saturday and Sunday. 

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
Conditions are favored to trend drier Sunday night as the low
center crosses east of the Cascades. Can't rule out lingering
showers over the mountains. An upper level ridge will begin
to build offshore on Monday, introducing a slow warming trend
through midweek. Some ensembles suggest weak troughing
Tuesday-Thursday that could bring some PoPs to the region, but 
for now, looks like dry and warm conditions will manifest.


&&

.AVIATION...
Northwesterly flow aloft becoming westerly this morning and
southwesterly this afternoon as an upper level low moves south
near 130W. Weak onshore flow in the lower levels. 

VFR ceilings early this morning. Widespread MVFR ceilings
developing 13z-16z lasting into early afternoon. VFR all areas
by mid afternoon with VFR ceilings continuing into Saturday
morning. 

KSEA...MVFR ceilings developing 14z-16z with ceilings lifting
back to VFR 20z-22z. VFR ceilings continuing into Saturday 
morning. South wind 4 to 8 knots becoming southwest this 
afternoon. Wind switching to northerly 4 to 6 knots around 03z.
Felton

&&

.MARINE...
High pressure over the waters will weaken today. A weak system 
will move through the offshore waters into Oregon tonight and 
Saturday. High pressure will rebuild over the coastal waters 
Sunday and remain through Tuesday.

Possible small craft advisory winds in the Central and Eastern
Strait of Juan de Fuca Saturday night. 

Seas 5 to 7 feet today and a little choppy. Seas subsiding to 3
to 5 feet Saturday with 3 to 5 foot seas continuing into the
first half of next week. Felton


&&

.FIRE WEATHER...
A return to onshore flow will maintain cooler and more moist 
conditions across western Washington through the weekend. Light
precipitation is likely into Saturday as another weak system 
moves over the region with a slight chance (15-20%) of
thunderstorms. Conditions are expected to gradually warm and 
dry into next week, though fire weather concerns remain low at 
this time.

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Small Craft Advisory until 5 AM PDT early this morning 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.

&&

$$