FXUS66 KPQR 260506
AFDPQR



Area Forecast Discussion

National Weather Service Portland OR

1006 PM PDT Tue Jun 25 2024



.UPDATED AVIATION DISCUSSION.



&&



.SYNOPSIS...

Low pressure will arrive later tonight and Wednesday,

bring cooler temperatures, clouds and even a few showers. Best chance

of showers will be Wednesday night. Dry and mild for Friday into

Saturday. But, another low pressure arrives, bringing another bout of

cooler temperatures and better chance of showers for Sunday into

early next week.



&&



.SHORT TERM...Tuesday night through Friday... One more rather 

summery feeling evening, under mostly clear skies. Low pressure 

offshore will be approaching overnight, and will allow for 

increasing onshore flow and cooler marine air to filter from the

coast to the interior overnight. 



That offshore low pressure will bring much cooler conditions to the

region on Wednesday. Will also see much more in way of clouds late

tonight into Wednesday. Overall, temperatures will stay in the 60s

along the coast, and lower to mid 70s across the interior. Will

maintain some chance of showers along the coast and across the

southwest Washington zones for Wed, but not all that convinced will

get much over the Oregon part. Bulk of the upper support for showers

seems to be farther to our north. So, will trend forecasts as such,

with generally dry weather for areas to the south of a Newport to

Portland line, and fairly decent chances (over 70%) for areas of the

higher terrain of southwest Washington, including the Willapa Hills

and the Cascades. Better chance of showers is Wed night, as another

upper disturbance in the flow shifts inland. With this one a bit more

south, more reasonable to support higher chances for showers over

much of the region. Still, rainfall (for those lucky) will be quite

variable, with 0.15 up to 0.33 inch generally for southwest

Washington and far northwest Oregon, down to a trace to 0.10 inch

across Lane County. 



Showers lingering into Thursday. After morning clouds, will see

clouds gradually break up through he afternoon. Mild day, with highs

in the 60s along the coast, and lower to middle 70s inland. 



High pressure rebounds over the region for Thu night and Friday. As

such, Friday will be a somewhat warm day for the interior, with highs

in the upper 70s to lower 80s for the interior, and mid to upper 60s

along the coast. All and all, not bad for late June. 



.LONG TERM...Saturday through Tuesday...Weak ridging into early

Saturday will give way to another trough. This next system will bring

a better chance of showers, mainly later Sat night through Sun

evening. Temperatures stay on cooler side, thanks to clouds. Overall,

looks like upper 60s to mid 70s at most for highs, with warmest well

inland. Still unsettled into early next week, as upper trough still

hanging over the Pac NW. Will maintain chance of showers for Monday,

and could be even for Tuesday. Models still in flux a bit for

Tuesday, as could be dry as well. But, temperatures slowly moderating

back to seasonal levels by Tuesday, with upper 60s on the coast and

mid to upper 70s inland. /Rockey





&&



.AVIATION...Tonight, an upper trough approaching will increase 

southwest flow inducing stronger onshore flow at the low levels. 

This will likely bring stratus to the coast through Wednesday 

morning with LIFR cigs already in place at KONP. Probabilities of

CIGs MVFR to IFR increase to 70-90% around 09Z Wed near KAST. 

Chances for rain showers also increases along the north oregon coast

by Wed afternoon. Guidance also suggests that marine stratus 

begins to push into the southern Willamette Valley after 12Z Wed 

with a 60-80% chance of MVFR near KEUG through 18-19Z Wed. 



PDX AND APPROACHES...VFR under mostly clear skies through tonight.

Approaching front will bring increasing mid to high level clouds

on Wednesday with a 30-40% chance for a period of MVFR cigs around

15-18z. Northwest winds 4-6 kt shift southwesterly by 10-12Z Wed.

-Schuldt



&&



.MARINE...

High pressure weakens as a weak front approaches the

waters. North to northwesterly winds around 10-15 kt ease

overnight followed by a southerly wind reversal Wednesday morning.

Winds are expected to remain below 20 kt. High pressure builds

across the waters again for Thursday and Friday, bringing a return

of northerlies. Seas remain in the to 4 to 6 ft range through 

most of the week as a westerly swell moves across the waters.



&&



.PQR WATCHES/WARNINGS/ADVISORIES...

OR...None.

WA...None.

PZ...None.

&&



$$



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