668
FXUS66 KPQR 292150
AFDPQR

Area Forecast Discussion
National Weather Service Portland OR
250 PM PDT Sun Jun 29 2025

.SYNOPSIS...Hot weather continues through Tuesday. The hottest
day is expected to be Monday, with widespread highs in the low
to mid 90s across interior valleys. There is a 10-20% chance
for isolated thunderstorms over the Lane County Cascades Monday
and Tuesday. Cooling follows midweek with temperatures into the
low to mid 80s, though temperatures will remain above seasonal
norms.

&&

.DISCUSSION...Sunday afternoon through Friday...Satellite
imagery this afternoon shows mostly clear skies across NW Oregon
and SW Washington as high pressure over the Desert SW builds
northwest into the region. Temperature observations at 2pm
Sunday show inland conditions in the low to mid 80s and 70s
along the coast, except for 60s along the central Oregon coast
where stratus is lingering. Temperatures are on track to peak in
the upper 80s to near 90 in the Willamette Valley today. High
pressure continues building into Monday, allowing temperatures
to continue warming. Monday will be the hottest day of the week
with temperatures peaking in the low to mid 90s inland. NBM
indicates a 70-90% chance of daytime temperatures reaching or
exceeding 95 degrees for valley locations north of Corvallis and
a 40-60% chance for locations south of Corvallis. High pressure
begins receding somewhat on Tuesday, though temperatures are
still forecast to peak near 90 degrees again. However, morning
low temperatures through Tuesday will cool into the upper 50s to
low 60s, which will keep HeatRisk designation in the Moderate
instead of Major category except for portions of the Columbia
River Gorge where overnight temperatures remaining in the low
70s bump that area up to Major HeatRisk on Monday. Although this
heat event is brief and does not currently meet criteria for
excessive heat headlines, sensitive populations - especially
those without access to cooling or spending time outdoors - are
still at risk for heat related impacts.

Along with warming temperatures, this high pressure will pull
monsoonal moisture north from the Desert SW into Oregon Monday
into Tuesday. However, latest guidance continues indicating the
majority of this moisture will remain just south and east of the
forecast area, with a small amount possibly making it just north
enough to clip the Lane County Cascades. Soundings indicate
enough instability across the Cascades (MUCAPE > 500 J/kg) that
if enough moisture does push into the Lane County Cascades that
there`s a 10-20% chance that a thunderstorm or two may be
possible Monday evening/overnight and again Tuesday
afternoon/evening. The main impact from any thunderstorm would
be lightning and gusty winds.

By Wednesday, guidance indicates the high pressure will have
moved east of the region as a weak troughing is expected to move
into the region, continuing through the rest of the week. This
will cause a return of weak onshore flow as well as cooler
temperatures. Expect inland high temperatures in the low to mid
80s and coastal temperatures in the 60s to low 70s through the
end of the week. -HEC

&&

.AVIATION...VFR through the next 24 hours. Northerly winds
throughout the area with gustiest conditions along the coast.
Satellite shows IFR broken CIGs south of KONP - likely due to
upwelling. These clouds will dissipate through the remainder of
the day. Overnight, scattered clouds will fill in once again at
around 200 ft AGL. There is a 25% chance of IFR CIGs south of
KTMK due to a slight onshore push. Confidence is low so have
maintained VFR conditions but cannot truly count those conditions
out.

PDX AND APPROACHES...VFR with northerly winds. Gusts up to 25 kt
from 1500-3000 ft AGL after 02Z Mon. -Muessle

&&

.MARINE...High pressure over the area with a typical summer time
wind pattern. Northerly winds are beginning to really ramp up.
Gusts around buoys 46050 and 46029 are around 23 kt and will
increase slowly through the next 24-48 hours. Gusts up to 30 kt
likely south of Tillamook, especially in the far outer waters.
These wind speeds may not be observed by the local buoys. North
winds of 10-15 kt with gusts up to 25 kt within the inner waters,
especially in PZZ252 and PZZ253. Winds will maintain these speeds
through at least Tuesday. Seas will be a persistent 5-6 ft at 10
seconds except Monday night as the strongest winds kick in. Seas
will be greatly impacted by the wind waves on Monday and Tuesday
with significant wave heights rising to 7-9 ft at 9 seconds.

For the Columbia River Bar, the Small Craft Advisory has been
continued due to strong winds over the entrance to the bar. Winds
will begin to ease Monday after 5 AM with gusts of 15-20 kt. Given
the marginal nature of the decreasing winds have maintained the
advisory through Monday morning.-Muessle

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...None.
WA...None.
PZ...Small Craft Advisory until 11 AM PDT Monday for PZZ210.
     Small Craft Advisory until 11 AM PDT Monday for PZZ251>253-
     271>273.
&&

$$

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