376
FXUS66 KPQR 191746
AFDPQR

Area Forecast Discussion
National Weather Service Portland OR
1046 AM PDT Sun Jul 19 2026

Updated aviation and watches/warnings/advisories sections.

&&

.SYNOPSIS...A strengthening ridge will keep temperatures on an
upward trend through the first half of the week. Inland areas
will climb into the upper 80s to maybe 90 today and Monday, then
see the hottest conditions Tuesday and Wednesday when many
valleys rise into the upper 80s to mid 90s. Dry weather will
persist, and heat-related impacts will become a growing concern
across the interior lowlands before temperatures ease slightly
late week.

&&

.DISCUSSION...Now through Saturday...The forecast pattern early
this morning remains dominated by building high pressure over
the western U.S., with the core of the ridge centered near the
Great Basin and extended northwest into the Pacific Northwest.
This setup will continue to favor a warming and drying trend
across southwest Washington and northwest Oregon through at east
midweek. Even though weak onshore flow near the surface
persists, especially closer to the coast, it will only modestly
slow the warming rather than stop it. As a result, temperatures
will continue to rise each day inland, while coastal communities
stay cooler but still trend a bit warmer as well.

Today will mark another step upward in temperatures, with most
interior lowland locations reaching the upper 80s to maybe 90
degrees by the late afternoon. The warmest temperatures should
occur in the typically hotter valleys, while the coast remains
in the mid 60s to mid 70s under continued marine influence.
Higher terrain will also warm efficiently today, with many
mountain and foothill locations rising into the upper 70s and
80s.

The hottest stretch of the forecast appears to be Monday
through Wednesday as the ridge reaches maximum strength.
Confidence remains fairly high that Monday will bring widespread
upper 80s to lower 90s across the interior lowlands. After
that, the forecast becomes a bit less certain for Tuesday and
Wednesday. Much of that uncertainty is tied to moisture and
cloud trends over the eastern Pacific, including a low off the
California coast and the potential for remnant tropical moisture
to become entrained into the broader pattern. If that moisture
spreads north, even subtle increases in cloud cover could have a
noticeable effect on high temperatures. Ensemble guidance and
cluster analysis continue to show this uncertainty by carrying a
broader range of possible outcomes in the middle of the week.
With that said, recent cluster analysis looks to have trended a
bit more drier compared to previous runs.

Even with those details still being worked out, confidence
remains high in the broader message: Tuesday and Wednesday are
still favored to be the hottest days for much of the interior.
Probabilities remain supportive of widespread 90-degree highs
across inland valleys, with the best chances occurring Tuesday
and Wednesday. Some of the warmest locations also have a
reasonable shot at reaching the mid 90s, especially if cloud
cover remains limited. With multiple days of above normal heat
and only limited overnight cooling, expect at least Moderate
HeatRisk across most if not all of the interior lowlands. The
Portland/Vancouver metro now appears increasingly likely to
reach Major HeatRisk on Tuesday, with a few additional areas
also possibly reaching that risk if the warmer end of the
forecast verifies.

By Thursday/Friday, guidance still points towards a modest
weakening of the ridge as a broader trough begins to influence
the Pacific Northwest and nudges the heat eastward. That should
allow temperatures to edge downward a few degrees late in the
week, though temperatures may still run somewhat above average
for late July. Dry weather is expected to continue through much
of the period, though there is a low-confidence potential for a
shortwave trough to rotate eastward along a broader trough,
bringing a chance of light rain Friday into Saturday. ~12

&&

.AVIATION...Inland stratus has mostly dissipated along with
coastal stratus south of KTMK. MVFR/IFR coastal stratus north of
KTMK will dissipate by 19-21z Sun. Stratus likely to return along
the coast again Sunday night/Monday morning, but there is
uncertainty amongst the guidance on timing. Some guidance
indicates it could return as early as 03-06z Mon with others
holding off until 10-12z Mon. Expect MVFR/IFR conditions again,
improving by 17-19z Mon. VFR conditions inland through the next 24
hours. Expect north to northwest winds 7-12 kt inland with
occasional gusts up to 15-20 kt and 10-15 kt along the coast with
gusts up to 25 kt. Winds decrease by 04-08z Mon.

KPDX AND APPROACHES...VFR conditions expected through the next 24
hours. Light northwest winds around 5 kts build to 8-10 kt by
21-22z Sun. Winds decrease by 06-08z Mon. -03

&&

.MARINE...A typical summertime pattern will continue through
early next week with persistent north to northwest winds over
the coastal waters. Winds will be strongest during the afternoon
and evening hours each day, especially today for the waters
south of Cape Falcon. Expect wind gusts up to 25 kt over the
central and southern waters today, with seas becoming steep due
to a fresh northwest swell around 6-7 ft at 7-8 seconds. By this
afternoon, these gusty winds and steep seas will expand into
the waters north of Cape Falcon. Between the increasing winds
and steepening seas, conditions will become hazardous to small
craft. As such, Small Craft Advisories are in effect for the
waters south of Cape Falcon through this morning, then for all
the waters this afternoon through early Monday morning.

Winds decrease below 20 kts early Monday morning, with seas
becoming less steep through the day as the swell decreases.
Benign conditions expected Tuesday into late next week. ~12

&&

.PQR WATCHES/WARNINGS/ADVISORIES...

OR...Heat Advisory from 10 AM Tuesday to 11 PM PDT Wednesday for
     ORZ108-109-111-112-115-119>122.
WA...Heat Advisory from 10 AM Tuesday to 11 PM PDT Wednesday for
     WAZ204>207-209-210.
PZ...Small Craft Advisory from 2 PM this afternoon to 5 AM PDT
     Monday for PZZ251-271.
     Small Craft Advisory until 5 AM PDT Monday for PZZ252-253-272-
     273.
&&

$$

www.weather.gov/portland

Interact with us via social media:
www.facebook.com/NWSPortland
x.com/NWSPortland