490
FXUS66 KSEW 140953
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
253 AM PDT Mon Jul 14 2025

.SYNOPSIS...A brief reprieve in warm temperatures is expected on
Monday as a system slides southward from British Columbia and
skirts the area. Warmer and drier conditions will return Tuesday
through Thursday, with some lowland locations potentially seeing
highs in the 90s by Wednesday. Elevated fire weather conditions
are also expected during this warm up. A cooling trend then
commences late in the week and into next weekend.

&&

.SHORT TERM /TODAY THROUGH WEDNESDAY/...A brief and somewhat
respite from the heat today with stronger onshore flow and a
trough moving down from B.C. Interior temps are forecast in the
70s today or closer to average. The coast will remain cooler and
in the 60s with northwest winds. Showers with the trough are
mostly north of the border and east of the crest.

The heat is back on Tuesday and Wednesday as heights rebuild, with
the ridge now centered offshore near 140W, and a thermal trough
forming iver the region. Highs in the interior will reach the 80s
to low 90s on Tuesday, with widespread 90s on Wednesday - leading
to Moderate HeatRisk. At the coast, the beaches will be in the
60s with 70s-80s a few miles inland. Winds aloft on Tuesday will
turn more N/NE which may bring Canadian wildfire smoke into
western WA. Per HRRR smoke forecasts, the smoke concentrations
look to be mainly aloft. The flow will turn westerly on Wednesday
for less smoke intrusion over the westside. 33

.LONG TERM /THURSDAY THROUGH SUNDAY/...Weak onshore pushes will
bring cooler conditions to the coast Thursday-Friday, but
temperatures in the interior will remain warm and in the 80s.
A stronger push this weekend looks to finally brings temps back
to normal. No precip in sight. 33

&&

.AVIATION...Northwest to northerly flow aloft as an upper level
ridge remains offshore. VFR conditions at all terminals early this
morning will gradually give way to MVFR as marine stratus starts
to creep in from the coast. Expect conditions to lower around
12-15z throughout the interior terminals. Conditions will rebound
to VFR around 18z, the exception being KHQM where lingering marine
stratus will likely continue. Northerly surface winds this morning
turning somewhat southwesterly this afternoon. Winds will turn
back northerly tonight and lighten.

KSEA...VFR early this morning will start to lower to MVFR around
12z-15z as marine stratus nears the terminal. Conditions will
improve to VFR around 18z-20z and continue for the remainder of
the day. N winds this morning around 10 to 15 knots. Winds will
gradually lessen early this afternoon as winds turn southwesterly
for a couple of hours. Northerly winds will return around 00z.

Mazurkiewicz

&&

.MARINE...High pressure remains offshore giving way to light
onshore flow across the area waters. Diurnally driven westerly
pushes down the strait will continue over the next several days
with various strengths. A Gale Warning continues for the Strait
until early this morning. A Small Craft Advisory will continue for
the coastal waters for elevated winds and steep seas. Thermal
troughing looks to build along the coast through midweek, with
periodic increases of northerly winds through the area waters.

Coastal seas 6 to 8 feet will gradually increase to 8 to 10 feet
later this morning and will generally remain through the first
half of the week.

Mazurkiewicz

&&

.FIRE WEATHER...A passing disturbance Monday will bring a brief
relief from the very warm and dry conditions of the weekend. This
system will bring much stronger onshore flow, spreading widespread
clouds and cooler conditions. However, attention will then turn to
the return of high pressure over the region. Expect to see afternoon
RH values dip down close to critical thresholds Tuesday afternoon
with a thermal trough building north over the Cascades. While some
uncertainty remains with respect to how far north and west this
builds, expect to see at least some east component to the surface
winds near the Cascade gaps in zone 659 and perhaps portions of 657
and 658. Confidence is lower in seeing more widespread easterly wind
and speeds may not be strong enough to raise fire weather concerns
to critical, but this may serve to further reduce RHs. Additionally,
depending on the placement of the thermal trough, expect to see a
deeper mixed layer and increased instability with mixing heights
potentially rising into Wednesday. While confidence in the specific
timing of elevated fire weather concerns is still lower, the mid
week period bears close watching for both existing incidents and for
the potential for conditions to remain of concern if new ones were
to begin. Looking ahead to the end of the week, expect conditions to
remain warmer and drier than normal but forecast guidance continues
to exhibit a large range of potential scenarios that leave
confidence lower than normal. Cullen

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...Heat Advisory from noon Tuesday to 10 PM PDT Wednesday for City
     of Seattle-Downtown Everett / Marysville Area-Eastern
     Kitsap County-Eastside-Foothills and Valleys of Central
     King County-Foothills and Valleys of Pierce and Southern
     King Counties-Foothills and Valleys of Snohomish and
     Northern King Counties-Foothills and Valleys of Thurston
     and Lewis Counties-Foothills and Valleys of the North
     Cascades-Lowlands of Lewis and Southern Thurston Counties-
     Lowlands of Pierce and Southern King Counties-Lowlands of
     Western Skagit and Northwestern Snohomish Counties-Lowlands
     of Western Whatcom County-Middle Chehalis River Valley-
     Northern Hood Canal-Olympia and Southern Puget Sound-
     Shoreline / Lynnwood / South Everett Area-Southern Hood
     Canal.

PZ...Gale Warning until 6 AM PDT early this morning for Central U.S.
     Waters Strait Of Juan De Fuca-East Entrance U.S. Waters
     Strait Of Juan De Fuca.

     Small Craft Advisory until 5 AM PDT early this morning for
     Admiralty Inlet.

     Small Craft Advisory until 5 PM PDT this afternoon for Coastal
     Waters From Cape Flattery To James Island 10 To 60 Nm-
     Coastal Waters From Cape Flattery To James Island Out 10 Nm-
     Coastal Waters From James Island To Point Grenville 10 To
     60 Nm-Coastal Waters From James Island To Point Grenville
     Out 10 Nm-Coastal Waters From Point Grenville To Cape
     Shoalwater 10 To 60 Nm-Coastal Waters From Point Grenville
     To Cape Shoalwater Out 10 Nm.

&&

$$