726
FXUS66 KSEW 290315
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
815 PM PDT Tue Jul 28 2026

.SYNOPSIS...A weak front will exit the region tonight followed by
dry and mild weather Wednesday and Thursday. High pressure will
lead to warmer conditions on Friday. An upper level low will
shift inland Friday night and Saturday for cloudy and cooler
weather with a chance of showers. High pressure returns early
next week.


&&

.SHORT TERM /TODAY THROUGH THURSDAY NIGHT/...
Frontal system largely on the way out this evening with latest
satellite showing clear skies over much of the western CWA and some
break-ups over the eastern. Latest radar imagery remains quiet,
helping to affirm that W WA is on the back end of the front.
Inherited forecast remains on track. For further details, please
refer to the Previous Discussion section below.  18

From Previous Discussion...Broad low pressure will spin off B.C.
Wednesday and Thursday with generally dry and mild conditions over
western WA. Near the surface, onshore flow prevails, for a mix of
morning clouds and afternoon sunbreaks. Temperatures will track in
the 60s and 70s again, a degree or two shy of average. 33

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...Low pressure continues to
spin offshore on Friday while high pressure builds inland. The
air mass over western WA will be a little warmer and drier with
daytime temps in the low to mid 80s across the interior. The
coast will be in the 60s to lower 70s. The low starts to slowly
shift inland Friday night and Saturday with a chance of
showers. We may also see showers with a convergence zone over
the north sound Saturday afternoon with a chance of
thunderstorms in the North Cascades. The upper departs N/NE on
Sunday with a return to dry and stable weather. A weak upper
level ridge will lead to warmer conditions early next week with
interior lowlands seeing the 80s again. 33

&&

.AVIATION...
Southwesterly flow aloft, with low level onshore flow across western
Washington. Nonetheless, mostly VFR observed across the TAF sites.
VFR conditions the rest of the evening but ceilings will lower again
to 2500 to 3000 ft, with some areas below 2000 ft by early Wednesday
morning.

KSEA...VFR ceilings above 5000 feet through tonight. Both LAMP and
REFS guidance showing a 25-35% chance of of a brief period of
ceilings less than 3000 feet around 14-16z. Southerly winds easing
this evening, and then are expected to shift to northerly. 75% of
REFS members have this shift by 04Z.

41

&&

.MARINE...
High pressure will return to area waters Wednesday through Friday.
Another weak system will reach the waters over the weekend. Periods
of small craft advisory winds remain possible with onshore flow via
the Strait of Juan de Fuca particularly Thursday evening and again
Friday evening into Saturday morning. Seas over the coastal waters
are expected to remain in the 4 to 5 foot range into the weekend.


&&

.FIRE WEATHER...
Drier and warmer conditions return Wednesday through Friday, with
minimum humidity values dipping into the 30s on Friday. However, low-
level flow remains onshore to provide for good to excellent
overnight recoveries, and this looks to be a short-lived trend as
the pattern shifts back to cooler and cloudier conditions for the
weekend.

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...None.

&&

$$