654
FXUS66 KSEW 090346
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
846 PM PDT Fri Aug 8 2025

.SYNOPSIS...Upper level ridging over Western Washington will
maintain a dry and warmer pattern into early next week. Moderate
HeatRisk is expected for Sunday and Monday across the interior,
with highs in the 80s and low 90s. The ridge will weaken on
Tuesday and upper level troughing will settle over the area
through late in the week. This will bring cooler temperatures to
Western Washington.

&&

.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...Forecast remains on
track with no changes this evening. Previous short and long term
sections follow.

An upper level ridge will bring dry and warmer conditions
through Monday. Another round of marine stratus is in store for
Saturday morning, but it should primarily remain confined to the
immediate coast. The stratus will scatter in the afternoon,
giving way to mostly clear skies across Western Washington. High
temperatures on Saturday will be in the upper 60s to low 70s
across the coast and mid 70s to low 80s across the interior.
HeatRisk on Saturday will be in the Minor (yellow) category for
the majority of the area. The warmest days are still on track to
be Sunday and Monday, with Monday being the warmest day. High
temperatures on Sunday and Monday along the coast will be in the
mid to upper 70s. Across the interior, high temperatures will
be primarily be in the 80s. Some locations along the Cascade
foothills and southern interior are likely to see high
temperatures in the 90s. Consequently, HeatRisk will increase
into the Moderate category (orange), with Moderate HeatRisk
being more widespread on Monday. In addition, overnight relief
will be limited Sunday and Monday, particularly across the
Cascade foothills, where overnight low temperatures are expected
to be in the low 60s.

.LONG TERM /TUESDAY THROUGH FRIDAY/...Long term guidance is in good
agreement that the upper level ridge will weaken on Tuesday and an
upper level trough will settle into the area midweek into late in
the week. There is some uncertainty regarding how much temperatures
will cool down on Tuesday. However by Wednesday, temperatures cool
down into the low 70s across the interior and the low 60s along the
coast. In addition to cooler temperatures, expect cloudier
conditions. The chance of light showers return Thursday into
Friday.

29

&&

.AVIATION...Northerly winds aloft as an upper level ridge builds
over western Washington. VFR conditions across the area with quite a
bit of mid and high level cloud cover. This should help to limit
where stratus/fog can develop, limited to along the coast and the
interior river valleys. Elsewhere, and through the day on Saturday,
VFR conditions will prevail. West/northwesterly winds will ease and
become light overnight before resuming again Saturday.

KSEA...VFR conditions through the period. Fog may form in the
valleys away from the terminal but no low clouds/fog are expected
Saturday morning. North/northeast winds up to 10 kt should ease
overnight, resuming tomorrow as northwesterly 8-12 kt.

62

&&

.MARINE...High pressure will gradually rebuild over the
northeastern Pacific this weekend through the start of next
week. Have maintained the advisory for the central and eastern
Strait this evening, but it looks marginal with gusts to 25 kt.
As high pressure builds over the waters, with a weak thermal
trough along the coastline, northwesterly winds will build over
the coastal waters early next week. Seas around 3 to 5 ft over
the coastal waters this weekend, building closer to 7 ft by
Sunday. Will need to monitor the steepness of these waves, which
may reach advisory criteria. More significant, seas over the
outer coastal waters will approach 10 ft Monday through the
first half of next week. Cullen

&&

.FIRE WEATHER...There`ll be good overnight RH recoveries tonight
into Saturday. The next elevated fire weather concern will be the hot
and dry pattern expected later this weekend into early next week
as ridging builds in over the area from the Pacific. Warming
temperatures, with highs in the 80s to low 90s and minimum
relative humidities dipping down into the 20s and 30s by early
next week will elevate fire weather concerns across portions of
the interior and in the Cascade foothills. Ensembles then suggest
troughing redeveloping across the region again by midweek, which
would help moderate temperatures and increase onshore flow.

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Small Craft Advisory until 2 AM PDT Saturday for Central U.S.
     Waters Strait Of Juan De Fuca-East Entrance U.S. Waters
     Strait Of Juan De Fuca.

&&

$$