FXUS66 KPQR 030445 AFDPQR Area Forecast Discussion...Updated Aviation National Weather Service Portland OR 944 PM 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. Near-seasonal temperatures continue through the weekend with warmer conditions possible next week. && .DISCUSSION...Wednesday Afternoon through Tuesday...A weak upper trough and associated surface cold front are approaching NW Oregon and SW Washington Tuesday afternoon. This has pushed high pressure to the east, allowing temperatures to fall much lower than previous days. Temperature observations at 2 PM PDT range from 5 to 15 degrees cooler than 24 hours ago, and high temperatures are forecast to peak in the upper 70s to low 80s across the Willamette Valley. Guidance shows this upper trough axis will remain situated just offshore of the West Coast through tomorrow, though the cold front will move inland tonight, breaking up as it moves through the region. No impacts are expected with this front except for temperatures cooling another few degrees tomorrow, back to seasonal normal for early July of upper 70s to 80 degrees across the Willamette Valley. Ensembles are in good agreement that the upper trough will move inland tomorrow night into Friday morning. This could produce a few light showers over the Lane County Cascades during this time period. At this point, uncertainty is too low to determine if there's enough instability for thunderstorm formation with these showers, but will be monitoring the forecast for this possibility. Temperatures Friday will be another few degrees cooler, topping out in the mid to upper 70s inland. Ensemble guidance indicates either more zonal flow or very weak troughing over the PacNW Saturday into Monday, which will allow for inland temperatures to increase a few degrees each day back into the mid to upper 80s by Monday. By Tuesday, 90% of GFS, Euro, and Canadian ensemble members indicate high pressure over the Desert Southwest will again push north into the PacNW. This would push daytime temperatures back into the 90s inland on Tuesday, possibly continuing later in the week. There's some uncertainty in exact numbers, but the spread between NBM 25th percentile and 75th percentile values keeps temperatures somewhere in the 90s. Additionally, NBM indicates a 30-60% chance of temperatures reaching or exceeding 95 degrees on Tuesday. -HEC && .AVIATION...VFR conditions for all inland terminals throughout the period. Northern coastal TAF sites (KAST) may continue to see marine stratus, as high-resolution models show a 75-80% chance of MVFR cigs or lower remaining in place through the entirety of the TAF period. Winds are continuing to decrease, with all terminals seeing variable winds under 6 kts by 8z Thu at latest. Winds increase again come Thursday morning, with north-northwesterly gusts up to 15-18 kts possible at all terminals by 16-18z Thu. PDX AND APPROACHES...VFR throughout the period. North-northwest winds still gusting up to 15 kts, but will be coming down by 8z Thu to below 6 kts. NNW winds pick up again Thursday morning by 18z Thu, with gusts up to 15-18 kts possible again through the end of the TAF period. /JLiu && .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 Interact with us via social media: www.facebook.com/NWSPortland x.com/NWSPortland