FXUS66 KSEW 091626
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
926 AM PDT Thu Jul 9 2026

.SYNOPSIS...Weak high pressure aloft will lead to seasonal 
temperatures and dry conditions across Western Washington today.
A weak front will bring increasing clouds and cooler 
temperatures to the region Friday into Saturday along with a 
chance for a little rain. High pressure will strengthen once 
again for warmer and dry conditions Sunday through Tuesday. 
Cooler conditions return by the middle of next week as onshore 
flow increases. 

&&

.SHORT TERM /TODAY THROUGH SATURDAY/...Areas of stratus are 
dissipating this morning, with mostly sunny conditions expected 
this afternoon along with a few high clouds. No major forecast 
updates, previous discussion below.

Mostly high level clouds are drifting across the area this 
morning in zonal flow aloft while onshore flow near the surface 
begins to ease. With less in the way of low cloud coverage this 
morning, high temperatures across interior areas will see a 
little boost. Onshore flow ramps up once again late today ahead 
of a weak front that will reach the area Friday afternoon into 
Friday night. As with most fronts this time of year, the best 
precip chances will be restricted to the Olympic Peninsula and 
North Interior, but it's not out of the question to see a few 
sprinkles reach Seattle metro...just don't hold your breath on 
that. We will, however, see cooler temperatures and plenty of 
cloud cover that will linger into Saturday as a trailing upper 
trough comes onshore before lifting northeastward into British 
Columbia.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...For Sunday 
through Tuesday, we'll be on the northwest periphery of a 
monster upper ridge building over the Rockies and Northern Great
Plains. This will give us a mini warming trend with 
temperatures peaking in the lower (or mid) 80s in the warmest 
spots on Monday. Ensembles maintain anomalous upper troughing 
along the British Columbia coast into the middle of next week, 
but there's some disparity with regard to it's depth. We're 
quickly approaching the climatologically driest and warmest 
portion of the year in Western Washington. Most troughs 
approaching from the northwest by mid-July do little more than 
initiate increasing onshore flow to cool us down. Given that, a 
good day 7 forecast leans toward near climo temps and dry 
conditions.

27

&&

.AVIATION...Onshore flow continues this afternoon with a mix of
VFR/MVFR ceilings across the area. More rapid clearing is 
expected this afternoon with VFR conditions for most TAF sites 
by 17-19z. A stronger marine push is expected tonight into 
Friday morning with an 80% chance of at least MVFR cigs 
developing along the coast by 06-08z Fri and a 40-60% chance of 
widespread MVFR cigs pushing inland to Seattle by daybreak 
Friday.

Winds have settled overnight except for gusts up to 20-25 kts 
along the Strait of Juan De Fuca, impacting KCLM through 
Thursday. Elsewhere, winds remain lighter, generally less than 
8 kts.

KSEA...MVFR ceilings this morning. Ceilings are expected to 
lift above 5000 ft by 17-19z with a scattered to broken high 
cloud deck lingering. There are better chances (40-60%) for 
widespread MVFR cigs to return by 12-15z Fri. Winds will be 
light through the period, from the southwest through Thursday 
morning, becoming west to northwest in the afternoon.

&&

.MARINE...Surface high pressure over the coastal and offshore 
waters will remain in place today before weakening on Friday as 
a weak surface low shifts southward toward to just west of north
Vancouver Island. An associated weak frontal system will cross 
the waters Friday afternoon into Friday night with little 
impact. High pressure rebuilds over the coastal waters Sundayinto Monday. Diurnally driven increases in westerlies can be 
expected in the Strait of Juan de Fuca each the next several 
days. 

27

&&

.FIRE WEATHER...The current onshore pattern will continue 
through the weekend which will lead to continued excellent 
nightly RH recoveries. A ridge of high pressure briefly rebuilds
into the region early next week. While the onshore pattern will
largely remain in place, warmer daytime temperatures and clear 
skies will likely lead to RH values dipping into the 30s and 
20s, with the lowest values in the south interior and Cascades. 
This will allow fine fuels to continue to dry with elevated fire
weather conditions.

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Small Craft Advisory from 5 PM this afternoon to 2 AM PDT 
     Friday for Central U.S. Waters Strait Of Juan De Fuca-
     East Entrance U.S. Waters Strait Of Juan De Fuca.

&&

$$