511
FXUS66 KPQR 270455 AAA
AFDPQR

Area Forecast Discussion...UPDATED
National Weather Service Portland OR
955 PM PDT Wed Jun 26 2024

.SYNOPSIS...Mother Nature not sure on pushing summer into our
region, so she will give us alternating mix of warm summer days
and cooler showery spring days. Lots of clouds around overnight
into Thursday, along with a few showers as low pressure shifts
inland. High pressure will bring dry and bit warmer weather for
Friday into Saturday. But, its back to clouds and some showers
with seasonal temperatures for Sunday into early next week. Dry
and back to bit warmer weather as next week progresses.

&&

.SHORT TERM...Now through Saturday...Southwest flow aloft will
continue overnight into Thu, as broad low pressure area sits
offshore, centered just west of Vancouver Island. Meanwhile, a
weak upper level disturbance off the south Oregon coast will
shift inland across southwest Oregon tonight. Add to the mix a
weak front that extends from the low near Vancouver Island back
to the south roughly along long 127 (about 125 miles offshore).
Together all these systems will provide ample lift, and with
moisture in place, will see scattered showers for just about
anywhere for late this afternoon into Thursday morning. Does
appear best chance of showers will be focused over the higher
terrain (Coast Range, Willapa Hills, and the Cascades/foothills)
as the weak front comes onshore and across the region
overnight. Even so, any rainfall will remain on the lighter
side, with 0.01" to 0.15" of rain, with 0.10" as much as 0.25"
in the higher terrain. That said, could see few spots in the
coast mtns and the Cascades (north of Santiam Pass) 0.25" to
0.50" with heavier prolonged showers.

Not much change on Thursday, as will maintain moderate to strong
onshore flow. As such, will be plenty of clouds in the morning, with
clouds gradually breaking apart in the afternoon. Though shower
potential will be decreasing through the day, will maintain high
chance of showers over the higher terrain.

Once the upper trough shifts east of the Cascades, high pressure will
build across the region. At same time, will see thermal trough over
far southwest Oregon strengthen. This will bring back a north to
northwest flow in the lower to mid levels, which is a drying and
warming pattern. So, will see lot more sunshine across the region on
Friday, as well as Saturday. Temperatures jump up well into the 60s
along the coast, and 70s to near 80 across the interior. Suspect many
inland areas (from Portland/Vancouver metro southward through the
Willamette Valley, and in the Gorge to Hood River Valley) will get
back into the lower 80s on Friday, and again Saturday.

But...changes arrive again, as another upper trough approaches. Will
see increasing onshore flow later Sat afternoon, with clouds
increasing along the coast and over the Coast Range/Willapa Hills.
Could even see a shower or two in those areas.      /Rockey

.LONG RANGE...Back to cooler temperatures and increased onshore flow
as upper trough works its way inland over the Pac NW. Ensemble
members suggest the potential for the return of scattered showers,
40-60% for the coast and higher elevations and 15-35% for inland
valleys according to the NBM. Again, amounts look very limited at
this time. Ensembles show bit more uncertainty in the pattern early
next week, though in general the suggested patterns would bring
continued mild weather. Temperatures look to remain in the 70s for
inland valleys with mostly dry conditions, except for the potential
for lingering scattered showers Monday. -HEC

&&

.AVIATION...Strong onshore flow across the region this am, with
widespread VFR deck (mostly 4500 to 5000 ft), though still have
pockets of MVFR CIGS along the coast. Clouds will continue to
gradually breaking apart through this evening.

Air mass is slightly unstable, enough to get a few showers. Better
chance of showers overnight as weak front (about 125 sm offshore as
of 3 pm) shifts inland overnight. Generally, will remain VFR with
broken decks from 3500 to 6000 ft tonight into Thu am.

PDX AND APPROACHES...Onshore flow continues through Thu. VFR deck
this afternoon and overnight, with main deck at 4500 to 5000 ft. Will
see CIGS likely at 3500 to 4000 ft overnight and persist into Thu am.
Will maintain a small chance (25% or less) for showers into this
evening, with better chance overnight.        /Rockey
 &&

.MARINE...Broad low pressure offshore will maintain south to
southwest flow on the coastal waters, with winds mostly 10 to 15 kt.
Seas staying in the 4 to 6 ft range.

High pressure offshore will return a bit for Thu night through early
Sat. At same time, will see thermal low pressure over far southwest
Oregon into northwest California. As such, will get back into some
northerly winds, with gusts 20 kt in afternoons/evenings.

But, yet another low pressure arrives later Sat, with winds flipping
back to the west or southwest. Gradients weaker, so winds not
expected above 15 kt. Seas stay in the 4 to 6 ft range.


.LONG TERM...Saturday through Wednesday...


&&

.AVIATION...

&&

.MARINE...


&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...None.
WA...None.
PZ...None.
&&

$$

www.weather.gov/portland

Interact with us via social media:
www.facebook.com/NWSPortland
www.twitter.com/NWSPortland