Tornado in Oregon, August 6, 2025

Area Forecast Discussion
National Weather Service Portland OR
226 PM PDT Wed Aug 6 2025

.SYNOPSIS...Building high pressure will result in warm and
dry conditions through early next week. Daytime highs will
slowly climb towards the upper 80s for the coast and upper 90s
for inland locations by Sunday. Monday is slated to be the
hottest day for the forecast period with daytime highs for inland
locations likely reaching into the triple digits. If this trend
continues, hazardous heat should be expected and prepared for.

&&

.SHORT TERM...Tonight through Friday Night...Light and showery
precipitation will continue to dissipate through tonight. As the
sun rises on Thursday, a broad area of high pressure will
slowly start to deepen within the Eastern/northeastern Pacific.
This will bring a return of hot and dry conditions to our CWA.
Daytime highs on Thursday are expected to be in the 60s along
the coast, mid 60s to mid 70s for the Cascades and upper 70s to
upper 80s for the Willamette Valley. Friday expect daytime highs
to be 3 to 5 degrees fahrenheit warmer as the Pacific High
pressure spreads eastward. Overnight lows on Thursday (mid 40s
to mid 50s) and Friday (mid 50s to upper 50s) will provide a
bit of a reprieve from the daytime heat. However, the cool
overnight temperatures will not linger around past Friday night.
/42

.LONG TERM...Saturday through Tuesday...The major pattern shift
continues over the weekend into next week. Temperatures continue
to warm into the upper 80s and 90s with the potential for triple
digit highs on Monday. This will result in hazardous heat Sunday
and Monday. There is some good news as that models are showing a
breakdown on the upper level high pressure as well as the
system moving away from the western CONUS on Tuesday.

Afternoon highs are likely (85-95% chance) to exceed 90 degrees
across interior valleys both Sunday and Monday. Confidence
remains very high that temperatures will peak on Monday, when
some locations may see their first triple-digit temperature of
the year, with 60-85% chances of reaching 100 degrees along the
Willamette Valley. Dewpoints in the low to mid 60s will
additionally make conditions feel noticeably humid each
afternoon, while overnight temperatures may fail to fall below
60-65 degrees both Sunday and Monday nights, most likely across
the northern and central Willamette Valley, the Lower Columbia
and Cowlitz Valleys, the Portland/Vancouver Metro, and along the
Columbia Gorge. This lack of sufficient overnight cooling can
raise the cumulative heat stress and elevate the risk for heat
illness, resulting in areas of Major HeatRisk. Residents of the
aforementioned areas should therefore begin to plan for this
period of hazardous heat. /42-Picard

&&

.AVIATION...Complicated weather day as a stalled cooler front
lingers over the Pacific Northwest. While much of the
precipitation has ended, the stratus remains anchored inland. CIGs
and VIS along the coast have fallen drastically compared to what
earlier models were suggesting. Visibility around 1 SM with CIGs
around 400 ft are present at almost all coastal runways. Inland,
MVFR CIGs dominate though they are flirting right at that OVC030
level. Will continue to monitor, but with nighttime cooling,
easily could see the lower atmosphere saturate out and CIGs lower.

Winds are the only other real concern today. The coast has once
again over-performed with gusts as high as 25 kt reported.
However, these conditions do appear to be localized. As the front
fully exits, winds will ease both inland and along the coast. With
light northerly winds overnight near KEUG, one thing to watch is
the potential for fog. This is a common pattern for patchy fog
there so cannot rule it out. Ultimately it will come down to how
much cloud cover lingers.

PDX AND APPROACHES...MVFR through most of the next 24 hours with a
period of lifting CIGs starting Thu afternoon. Winds will slowly
transition to the northwest behind the front. There is a slight
chance (10%) for thunderstorms on the east side of the terminal
this evening, but given a lack of mixing, that would be incredibly
difficult to achieve. 								-Muessle

&&

.MARINE...Transitioning into the post-frontal stage of this system
that brought rain and breezy winds along the inner waters.
Currently, there are some reports of gusts up to 25 kt through
land bound observation sites. These have yet to be observed
directly along the coast or by area buoys. While those winds are
possible, cannot rule out that it is a very localized feature.
Thus, have not issued any Small Craft Advisories at this time. For
those moving through the Columbia River Bar, note that wind gusts
will be high at times. Seas remain settled at 6 ft 10 seconds over
all of the observations. Seas of this magnitude are expected
through at least Friday.

Over the weekend, a ridge will build with a northerly wind
reversal and conditions will take on a typical summer pattern. As
temperatures warm considerably through the weekend, expects winds
to ramp up with combined seas being dominated by the wind wave.
High probability of Small Craft Advisory conditions starting
Friday afternoon.									-Muessle

&&

.PQR WATCHES/WARNINGS/ADVISORIES...

OR...None.
WA...None.
PZ...None.

&&

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