Wilsonville, Oregon 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

173
FXUS66 KPQR 220529 AAA
AFDPQR

Area Forecast Discussion...UPDATED
National Weather Service Portland OR
1029 PM PDT Sun Jun 21 2026

Updated aviation and marine discussions.

.SYNOPSIS...Over the next 5 to 7 days we`ll get to experience a
bit of everything weather-wise as we go from hot/dry to cooler
and wet. The hottest days of the week are expected on Monday and
Tuesday with inland high temperatures punching into the 90s
accompanied by widespread Moderate to near Major HeatRisk
values. A Heat Advisory is in effect for the inland valleys
Salem northward through the Portland Metro/SW Washington
including the Columbia River Gorge. Fairly warm overnight
temperatures may provide a limited window of overnight relief in
our urban centers. Temperatures begin to slowly trend cooler
Wednesday with moderate to high confidence in a cool and wetter
pattern (by June standards) taking hold to end the week.

&&

.DISCUSSION...Today through Saturday...Skies have completely
cleared this afternoon thanks to a ridge of high pressure
amplifying just off the coastline. This ridge feature will help
facilitate a period of abnormally warm conditions to start the
work week as it progresses overhead with the majority of
guidance pointing to high temperatures exceeding 90F across the
inland valleys of southwest Washington and western Oregon Monday
and Tuesday. However, compared to yesterday, NBM model guidance
has decreased projected high temperatures by ~1-4 degrees
across the inland valleys areas while also nudging overnight
minimum temperatures a touch lower as well. This correction may
be due to the NBM finally being within the time period to ingest
shorter-range high resolution guidance, and/or better ensemble
agreement on the eastward placement of the surface thermal
trough axis. Nonetheless, heat related impacts may still be
felt from the Central Willamette Valley through the Portland
Metro, Columbia River Gorge, and the southwest Washington
lowlands where a Heat Advisory is in effect through Tuesday
evening.

For those hoping to see us rise into the triple digits Mon/Tue
those chances are waning but still worth pointing out as the NBM
maintains a 10-30% chance for the central/south Portland metro
to meet or exceed 100F Tuesday afternoon. We`ll see how these
probabilities evolve come tonight/tomorrow`s forecast although
they`ll likely continue to drop given the latest trends and
overall set-up not appearing conducive for 100+ degree
temperatures as we maintain weak NNW flow on Tuesday. If you`re
a glutton for truly hot conditions you`d want a much stronger
easterly component of the low-level flow (surface-850mb), the
surface thermal trough axis placed along the coastline or just
offshore, and a stronger ridge of high pressure overhead - in
this case it`s weakening temporally. That said, temperatures are
still expected to be 15-20 degrees above normal even without
the aforementioned variables aligning. Make sure to stay
hydrated, wearing light-colored and loose-fitted clothing,
wearing sun protection, and taking frequent breaks from the
heat. If possible, schedule outdoor plans during the early
morning or late evening when temperatures will be less intense.

Then on Wednesday the vast majority of ensemble members kick
the broader upper-level ridge axis east of the Cascade crest-
line during the daytime hours. This should allow for high
temperatures to drop a few degrees into the upper 80s to low 90s
across the interior lowlands although the greatest day the day
temperature change will likely be felt along the coast and in
the some of the coast range valleys as westerly flow begins to
increase in earnest. The latest NBM still gives a 20-50% chance
for highs to exceed 95 degrees Wednesday afternoon from Salem to
the Portland- Vancouver Metro - something to watch. At least
confidence is very high temperatures begin a noticeable descent
back to normal, then below normal, the remainder of the week as
the upper-level pattern undergoes a significant shift.

Thursday through the start of the weekend the majority of
deterministic and ensemble guidance are depicting a upper-level
trough of low pressure moving into the Pacific Northwest
ushering in a cooler and wetter pattern. There still remains
some uncertainty with the exact timing, placement, and magnitude
of the trough, and thus there is uncertainty regarding exact
precipitation amounts. The latest ensembles, including the NBM,
are highlighting late Thursday night into Friday morning as best
chance (60-95%) for rainfall during this late week period,
mainly focused along the coast, coast range, Portland Metro
through SW Washington, and in the Cascades. Should the core of
the upper-level trough/low track overhead Friday and Saturday,
post-frontal thunderstorms are another concern we`ll have to
watch. At the end of the day, any precipitation be can get this
time of year is largely beneficial and we`ll take what we can
get during this late week/early weekend period. -99


&&

.AVIATION...Satellite and surface weather observations from 0530Z
Monday showed low marine stratus beginning to fill in along the
coast with ceilings around 700-800 ft. Expect this stratus deck to
linger through tonight at the coast, before scattering out and
pushing back offshore around 17-18Z Monday. However, there is a
30-40% chance low clouds will fail to clear out at KONP on
Monday.

Meanwhile, inland areas will remain clear with VFR conditions.
Light winds tonight will increase out of the north late Monday
morning into Monday afternoon to 7-11 kt. Winds may occasionally
gusts as high as 15-18 kt between 22Z Monday and 03Z Tuesday,
except up to 20 kt at KONP.

KPDX AND APPROACHES...Clear skies will maintain VFR conditions
through 06Z Tuesday. Northwest winds around 7 kt this evening
should become light and variable around 08Z Tuesday. Winds
increase out of the north after 20Z Monday with gusts up to around
15-17 kt by late Monday afternoon. -23

&&

.MARINE...Northwesterly winds will generally stay under 20 kt
through Monday morning, aside from occasional small craft
advisory wind gusts up to 21 kt over the outer waters. Seas will
remain steep and choppy around 5-7 ft in the outer waters through
at least Tuesday morning. High pressure re-builds Monday
afternoon into Tuesday, tightening pressure gradients and
increasing north-northwesterly winds with gusts up to 25 kt. Small
Craft Advisories are in effect for the outer waters (beyond 10 NM
offshore) until 5 AM Tuesday for the waters south of Cape Falcon.
For the outer waters north of Cape Falcon, the Small Craft
Advisory is in effect until 5 AM Monday. Expect seas of 5 to 7 ft
through most of this upcoming work week. There is only a 10-20%
chance for seas exceeding 7 feet at any given hour from Monday to
Wednesday. -23/10

&&

.PQR WATCHES/WARNINGS/ADVISORIES...

OR...Heat Advisory from 11 AM Monday to 11 PM PDT Tuesday for
     ORZ108>115-119>123.

WA...Heat Advisory from 11 AM Monday to 11 PM PDT Tuesday for
     WAZ204>210.

PZ...Small Craft Advisory until 5 AM PDT Monday for PZZ271.

     Small Craft Advisory until 5 AM PDT Tuesday for PZZ272-273.
&&

$$

www.weather.gov/portland

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