FXUS66 KPQR 021015

AFDPQR



Area Forecast Discussion

National Weather Service Portland OR

315 AM PDT Wed Jul 2 2025



.SYNOPSIS...Onshore flow returns today which will bring in

cooler and more moist air. Stronger westerly flow will cause

winds to increase in the Columbia River Gorge and Upper Hood

River Valley through today. 



&&



.SHORT TERM...Now through Friday...The upper level ridge which

brought high temperatures into the 90s is beginning to decay.

This will initiation the return of onshore flow and cooling

temperatures through the rest of the week. Overall, 850 mb

temperatures will fall to around 10 degrees C each day. There

will be a drastic drop in temperature today with highs only

forecast to reach 80 degrees in the Greater Portland-Vancouver

Metro 80-85 degrees in the southern Willamette Valley from

Corvallis South, in the low 80s through the Gorge, and 60s along

the coast. For those still dreaming of temperatures in the 90s,

you better head to the east as there is less than a 5% chance

anywhere in the forecast area. 



On Thursday into Friday a weak shortwave aloft will move over

the area. This will increase some convective behavior though

thunderstorms are not necessarily expected. However, some

showers are possible over the Lane County Cascades. As it passes

could see an increase of westerly winds through the passes,

though not expected to be impactful.



For those wanting to enjoy outdoor activities on the 4th,

prepare for seasonable temperatures, mostly clear skies, and no

rain. 												-Muessle 



.LONG TERM...Friday Night through Tuesday...The trough continues

to push inland through the weekend and ridging builds in behind

it. Will see a return of warmer conditions though flow will

continue to be onshore aloft. Therefore, conditions not expected

to be exceptionally warm until late in the forecast on Monday or

Tuesday. As we round out the weekend, flow will shift to the

north-northeast ushering in much drier and warmer air to the

region. A weak thermal trough will begin to form on Sunday

afternoon. At this point, the pressure gradient, combined with

the temperature gradient across the Cascades, will intensify.

Westerly winds will ramp up late Sunday afternoon. 



500 mb height ensembles are in fairly good agreement moving

forward with the ridge intensifying. Temperatures will rise by

around 5 degrees each day on Monday and Tuesday with around a

50% chance of exceeding 90 degrees on Monday through the

Willamette Valley, and 75% or more on Tuesday. 		-Muessle 





&&



.AVIATION...Marine stratus continues to support mixed IFR/low-

end MVFR cigs and occasionally restricted vis within mist at

coastal terminals including KONP/KTMK/KAST. The stratus deck has 

also pushed inland along the Lower Columbia as far as KKLS early

this morning, suggesting higher (50-60%) chances of MVFR stratus 

reaching Portland-area terminals including KPDX/KVUO/KTTD/KHIO by 

12-15z Wed than predicted in numerical or statistical guidance.

Stratus will then slowly erode inland through the morning while

remaining more entrenched with persistent MVFR/IFR cigs along the

coast. Otherwise, sct-bkn cirrus at 20-25 kft leftover from

earlier convection along and east of the Cascades will trend

clearer by 15-18z Wed, yielding continued VFR conditions. Diurnal

NW winds reaching 10-15 kt with gusts to 20 kt return after 

18-22z Wed, easing below 10 kt again by 03-06z Thu.



PDX AND APPROACHES...Ongoing VFR under bkn high cirrus deck may

continue beyond 12z Wed, with increasing likelihood of marine

stratus pushing inland along the Columbia River by 15z Wed 

resulting in MVFR cigs around 1500 ft. Any stratus will be favored

to mix out by 17-18z Wed, with VFR conditions otherwise expected

throughout the period. Diurnal NW winds around 5 kt will increase

to 10-15 kt by 21-24z Wed with gusts as high as 18-20 kt through

the afternoon, easing to less than 10 kt after 04-06z Thu. -Picard



&&



.MARINE...Persistent surface high pressure offshore will result in

continued north to northwesterly winds across the waters. Diurnal

gusts will reach 10-15 kt north of Cape Falcon and 15-20 kt from 

Cape Falcon to Florence each afternoon, easing to around 10 kt 

overnight. Seas will continue at 3-6 ft through the weekend. 

Strengthening surface high pressure will then see winds and seas 

build Sunday into next week. 							-Picard



&&



.PQR WATCHES/WARNINGS/ADVISORIES...

OR...None.

WA...None.

PZ...None.

&&



$$



www.weather.gov/portland



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