132
FXUS66 KPQR 191048
AFDPQR

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

.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...Currently VFR inland and a mix of MVFR/IFR CIGs
along the coast as of 11Z Sun. Coastal terminals will continue
to see these MVFR/IFR CIGs until 17-19Z Sun as marine stratus
continues to push into the coast (70-90% chance of MVFR CIGs,
30-50% chance of IFR CIGs). Conditions will improve to VFR
thereafter and persist until around 03-05Z Mon. Coastal terminal
conditions will then deteriorate back to MVFR/IFR CIGs and
remain so through the end of the TAF period (50-70% chance of
MVFR CIGs, 30-50% chance of IFR CIGs). As for inland terminals,
expect VFR conditions through the TAF period, with a 15-25%
chance of MVFR CIGs between 12-17Z Sun (highest chance at KTTD
due to the potential of stratus backbuilding off the Cascade
foothills). Otherwise, expect light north to northwest winds
early this morning to build to 7-12 kt with gusts up to 15-20
kt inland and 10-15 kt with gusts up to 25 kt at the coast by
midday Sunday.

KPDX AND APPROACHES...VFR conditions favored throughout the
period, with just a 15-25% chance of MVFR CIGs between 12-17Z
Sun. Light northwest winds build to 5-10 kt by midday Sunday.
~12

&&

.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...None.
WA...None.
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

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