Happy Valley, Oregon 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

038
FXUS66 KPQR 242148
AFDPQR

Area Forecast Discussion
National Weather Service Portland OR
248 PM PDT Sun May 24 2026

.SYNOPSIS...High pressure continues to linger over the region
through the evening, but confidence remains high that a significant
pattern change is on deck starting tonight. The cause of this
cooler and wetter pattern is a Gulf of Alaska low that looks to
bring widespread rain, breezy winds, and much cooler temperatures
across the area. Showers linger into Tuesday along with a
slight chance (10-20%) for thunderstorms. Conditions trend
warmer and drier through the middle of the week and into next
weekend.

&&

.DISCUSSION...Now through Saturday...Clear skies this evening
will soon be replaced by widespread cloud cover starting
tonight. GOES full disk, satellite observations shows a broad
upper level low covering a vast area of the northeastern
Pacific Ocean. Putting the satellite on a loop, this low is
moving eastward which will result in a cold front being pushed
across the Pac NW. This front will bring widespread rain and
thick cloud cover across our CWA. Rain should begin along the
coast around 5AM-7AM Monday morning, with rain starting to
impact inland locations around 12PM-2PM Monday. Recent guidance
supports 24 hour rainfall totals (roughly 5 AM Monday to 5 AM
Tuesday) in the 0.15"-0.80", with the greatest totals along the
coast and Coast Range. Probabilities for at least 0.25 inch are
generally 35-75% for the Willamette Valley and 60-95% for the
coast, Coast Range, and Cascades. Probabilities for 0.50 inch
or more are generally 5-30% for the Willamette Valley and 60-95%
for the coast and Coast Range, and generally 15-45% for the
Cascades. A corridor from Florence OR north toward Seaside OR
continues to show the best chances, around 20-40% for 1.0" or
more.

Winds will also pick up early Monday as the front moves
through. Currently probabilities strongly favor gusts exceeding
25 mph across much of the area (around 80-99%). Gusts over 30
mph are more likely along the coast (60-90%) than inland
(25-60%). Higher-end gusts around 35 mph or greater remain a
lower-probability outcome for inland locations (5-15%) but are
more favored along the coast (30-50%). Even without advisory-
level winds expected inland, these speeds can still impact
tents, canopies, and other unsecured items.

By Tuesday, the low shifts southeastward with showers lingering
and a more southerly flow developing. That setup is more
supportive of thunderstorms, which is resulting in a 10-20%
chance for the Willamette Valley and Cascades by late Tuesday
morning through late Tuesday evening.

From midweek through next weekend, guidance trends toward a
warming and drying pattern as weaker high pressure/zonal flow
returning. For reference, daytime highs will likely (70-85%)
remain slightly cooler than this weekend. While confidence
remains low, ensemble guidance suggests that the weak high
pressure ridge will weaken Friday as a broad trough over the
Northeast Pacific nears the Pacific Northwest. /42~12

On a slightly personal note, with Monday being Memorial Day, it
is time to remember those who served that are no longer with
us. I want to remind everyone that if you are a fellow veteran
or know a veteran that needs help, you can always call the VA
Crisis Line by dialing 988 and pressing 1 or text 838255
24/7/365. We must take care of and look out those who stood
besides us, who came before us and who will follow in our
footsteps. Semper Fi. /42

&&

.AVIATION...Satellite imagery as of early Sunday afternoon depicts
mostly sunny skies with a few high clouds as dry westerly flow
prevails aloft. Will maintain predominately VFR conditions
through this evening with increasing SCT/BKN high clouds ahead of
the next system. This system will swing a cold front through the
coast after 12-15z Sun, returning light rain and a 50-70% chance
for MVFR CIGs at any given hour after 12z Mon for KAST/KONP.
Still some uncertainty with exactly when MVFR conditions return
along the coast, but guidance generally has marine stratus
arriving as early as 04-07z Mon (earliest for KONP). For inland
terminals, the front will return light rain and low-end VFR CIGs
after 18-21z Mon, with a 20-40% chance for MVFR CIGs across the
Willamette Valley. There is also a 10-20% chance for thunderstorms
across the area after 18z Mon which may produce lightning, brief
heavy downpours reducing VIS, erratic winds, and/or small hail.

Northwesterly winds turn more westerly this afternoon, turning
south-southwesterly tonight. Breezier southerly winds with gusts
up to 20-25 kt return after 09-12z Mon along the coast and after
12-15z Mon across the Willamette Valley as the front approaches.

KPDX AND APPROACHES...Predominately VFR conditions through the
TAF period with increasing SCT/BKN high clouds through this
evening ahead of the next system. West-northwesterly winds this
afternoon turn more southerly after 08-10z Mon ahead of the next
front. After 13-15z Mon, southerly winds increase with gusts up to
20 kt as the front approaches. CIGs also gradually fall to low-end
VFR after 19-21z Mon.      -10

&&

.MARINE...Northerly winds will gradually turn more southerly this
afternoon and evening ahead of the next frontal system. Tonight,
southerly winds increase with widespread gusts up to 30 kt across
all waters as the next front moves through. Peak winds are
expected between 5-11 AM Monday with a 50-70% chance for isolated
Gale force gusts up to 35 kt for the inner waters (from shore to
10 NM out) north of Cape Foulweather. After 11 AM Monday, winds
turn more west-southwesterly behind the front with gusts up to 25
kt. Small Craft Advisories are in effect from 11 PM Sunday
through 5 PM Monday for all waters including the Columbia River
Bar. Seas around 6 to 8 ft through early Monday morning.

Following the frontal passage, a westerly swell will move in a
build seas above 13 ft (>90% chance). There is also a 5-10% chance
for seas exceeding 20 ft Monday night into Tuesday morning, with
the highest chances for the outer waters beyond 30 NM offshore.
Given the potential for seas between 15-20 ft, there remains a
Hazardous Seas Watch for all waters including the Columbia River
Bar between 5 PM Monday to 11 AM Tuesday. Seas subside to 10-12
ft by Tuesday evening and gradually subside into Wednesday. Will
also note that there is a 10-20% chance for thunderstorms across
the waters Monday night. Any passing thunderstorms may produce
lightning, brief heavy downpours that reduce visibility, erratic
winds, and/or small hail.      -10

&&

.PQR WATCHES/WARNINGS/ADVISORIES...

OR...None.
WA...None.
PZ...Small Craft Advisory from 11 PM this evening to 5 PM PDT Monday
     for PZZ210-251>253-271>273.

     Hazardous Seas Watch from Monday afternoon through Tuesday
     morning for PZZ210-251>253-271>273.

&&

$$

www.weather.gov/portland

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