The Summit at Snoqualmie

000
FXUS66 KSEW 011032
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
332 AM PDT Sat Aug 1 2026

.SYNOPSIS...
A weak front will reach the coast this morning and move through
the interior this afternoon. Upper level trough arriving Sunday
moving east late in the day. Upper level ridge building 
offshore Sunday night moving over Western Washington Monday.
Temperatures warming Tuesday and Wednesday. Ridge weakening a 
little towards the end of the week for slightly cooler 
temperatures. 

&&

.SHORT TERM /TODAY THROUGH MONDAY/...
Satellite imagery shows weak cold front near 120W at 10Z this 
morning. Clouds out ahead of the front have reached the Cascades.
Rain started along the north coast around 09Z but has not gotten
much further inland. Temperatures were in the mid 50s to lower 
60s.

Front reaching the coast this morning moving through the
interior early this afternoon. Rain along the coast this
morning. With the front weakening as it moves inland showers
likely/chance of showers a few hours ahead, with and behind the
front for the interior mid morning through early afternoon.
Skies clearing late in the afternoon except over Snohomish
county where a Puget Sound Convergence Zone will form behind the
front. In addition to the precipitation breezy conditions
developing with and just behind the front with gusts around 30
mph in most locations. Highs in the 60s and lower 70s.

Weak upper level trofiness behind the front tonight with showers
becoming confined to the convergence zone by late evening. It's
going to be a cool early August morning Sunday with the colder
locations dropping into the 40s. For the remainder of the area
lows in the lower to mid 50s. 

Upper level trough moving into Western Washington Sunday. Trough
coming down from the north so not much moisture with it. The
little bit of lift it will provide could generate some showers
mostly over the North Cascades. Convergence zone over Snohomish
county dissipating late morning. Another cool day under mostly
cloudy skies with highs again in the 60s and lower 70s. 

Upper level trough moving east Sunday evening with an upper 
level ridge building offshore. Ridge moving towards Western 
Washington overnight. Clearing skies providing another cool 
morning with lows in the upper 40s to mid 50s. 

Upper level ridge building Monday. High temperatures warming but
still falling a couple of degree short of normal. Highs in the 
70s. 

For the first time since 2012 Seattle had below normal
temperatures for the month of July. The average temperature for
the month was 66.9 degrees. Normal is 67.1 degrees. There were 
9 days with highs 80 degrees plus. For the last 9 years ( 
2017-2025 ) Seattle has averaged 15 days in July with highs 80 
degrees plus. The last year there was less than 10 80 degree 
plus days was 2016. It was also the coldest July in Seattle 
since 2016 where the average temperature was 66.8 degrees ( 
normal temperature for July in 2016 was 65.7 degrees so it was 
still an above normal month temperature wise ). Felton

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
Models showing good consistency with a flat upper level ridge
over Western Washington at least through Wednesday. Some small
differences showing up in the models beginning Thursday with
some of the solutions weakening the ridge while other solutions
keep the ridge in the middle to upper 580 dms. Much warmer
Tuesday and Wednesday as the low level flow tries to turn
offshore. Highs in the 70s on the coast and upper 70s to near 
90 inland. With the stronger ridge solutions just introduced 
this model run will stay with the previous idea of a little 
cooler Thursday and Friday with highs near 70 coast and lower 
70s to lower 80s inland. 

Low level flow turning a little northerly Tuesday which could
pull some smoke from the fires in British Columbia down over the
area. Low level flow remaining northerly Wednesday before
turning back to a more westerly direction Thursday. Felton

&&

.AVIATION...Southwesterly flow aloft becoming more westerly into 
Sunday morning as a weak front pushes through. MVFR cigs are pushing 
west to east - increasing in coverage this morning. This activity is 
slated to persist along with rain showers before conditions improve 
into the afternoon. Gusty post-frontal west to southwesterly surface 
winds (25-30 kt) are expected at times today and a convergence zone 
is expected to develop later this afternoon/evening over Snohomish 
County. Latest guidance suggests the convergence zone will remain 
near PAE. Surface winds will trend lighter overnight with marine 
stratus rebounding becoming more widespread into Sunday morning. 

KSEA...Ceilings are lowering to MVFR this morning and will persist 
until 19-20z. Southwesterly surface winds will rise to 10 to 15 
knots with gusts to 20-30 knots this afternoon. Winds will gradually 
decrease overnight into Sunday morning. MVFR stratus likely to 
redevelop into Sunday morning as well before scattering into the 
afternoon.

41

&&

.MARINE...A weak frontal system is pushing across area waters today. 
Increasing onshore flow will lead to small craft advisory westerly 
winds in the central/east strait much of today. Additionally, post-
frontal onshore flow will lead to small craft advisory 
southwesterlies in Puget Sound/Hood Canal during today as well. High 
pressure will rebuild over the coastal waters Sunday and remain in 
place into early next week as thermally induced low pressure expands 
northward across the interior with light flow.

41

&&

.FIRE WEATHER...
Good chance for wetting rains along the north coast and in the
North Cascades today with the front. This along with cooler
temperatures will help ease fire weather concerns. There is a 
slight chance of thunderstorms in the North Cascades but if one 
does occur it will be accompanied by rain. Another cool day 
Sunday will keep fire weather concerns at a minimum.

Warming temperatures Monday with elevated fire weather concerns
beginning Tuesday with above normal temperatures and low level 
drying. Minimum relative humidity values again dropping into 
the 20s late in the afternoon over the southern portion of the 
area and the Cascade foothills both days. Elevated fire weather
concerns could continue through the end of the week if the 
small cool down does not materialize. Felton 

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Small Craft Advisory until 10 PM PDT this evening for Central 
     U.S. Waters Strait Of Juan De Fuca-East Entrance U.S. 
     Waters Strait Of Juan De Fuca.

     Small Craft Advisory until 10 PM PDT this evening for Puget 
     Sound and Hood Canal.

&&

$$