481 FXUS66 KPQR 121817 AAA AFDPQR Area Forecast Discussion...UPDATED National Weather Service Portland OR 1117 AM PDT Thu Jun 12 2025 UPDATED AVIATION DISCUSSION .SYNOPSIS...A persistent onshore flow regime will maintain seasonable temperatures through Wednesday of next week with high temps mainly in the 70s each day for inland areas and low 60s at the coast. Dry weather will continue aside from early next week when chances for light rain return to the area. There is also a 10-20% chance of light drizzle along the coast Thursday morning and Friday morning, mainly along the south WA/north OR coast. && .SHORT TERM...Thursday through Sunday night...The short term forecast is highlighted by a persistent onshore flow regime with temperatures close to average for this time of year and mainly dry weather through the weekend. Satellite and surface weather observations from early Thursday morning depicted low clouds over much of southwest WA, the lower Columbia, north OR Coast Range and north OR coast. Expect cloud cover to expand over the Portland/Vancouver metro and portions of the Willamette Valley and Cascade foothills towards sunrise. Areas that do see cloud cover Thursday morning will see an increase in sun during the late morning and afternoon hours. Temperatures will most likely top out in the low to mid 70s for inland valleys, however there is a 10-25% chance for highs in the upper 70s if enough sunshine occurs. Temps will remain cooler at the coast with highs around 60-63 degrees. Friday will be noticeably cooler as 850 mb temps cool several degrees with a passing shortwave trough aloft. This shortwave will also help deepen the marine layer slightly, resulting in a 10-15% chance of light drizzle at the coast and increasing chances for morning cloud cover for inland valleys, mainly to the north of Salem. The NBM 25th-75th percentile for high temps ranges from the upper 60s to lower 70s, with the deterministic NBM falling near the 50th percentile around 70 degrees. Given the cooler temps, Friday will be a great day for strenuous outdoor activities such as yard work, exercise, etc. Temps warm back into the mid 70s on Saturday for inland valleys and low to mid 60s at the coast in response to rising 500 mb heights, warming temps aloft and less morning cloud cover (aside from the south WA/north OR coast and Willapa Hills where mostly cloudy conditions are likely in the morning). Temps trend a few degrees warmer on Sunday, which is currently expected to be the warmest day of the week with the highest chance for highs of 80 degrees or warmer over inland valleys (20-40% chance). -TK .LONG TERM...Monday through Wednesday night...The long term forecast is highlighted by chances for light rain Monday night through Wednesday morning in response to an upper level trough. While most ensemble members from the 00z/June 12th iteration of the ENS/GEFS/GEPS show at least some measurable rain with this trough (generally under 0.1-0.2" with the highest amounts at the coast and the lowest amounts from Salem to Eugene), there are significant timing differences evident; some members bring rain into the area as early as Monday, while others hold off until late Tuesday. In addition, there is a small handful of members showing no rain at all, mainly from the GEFS/GEPS. Nevertheless, the NBM is showing a 20-40% chance for 48-hr rain amounts of 0.1" or more from 5am Monday to 5am Wednesday, except 50-60% across southwest WA and 60-75% along the coast. As if often the case this time of year, coastal locations and more northern locations are favored to see the most rain, assuming rain does occur with this system. -TK && .AVIATION...Impacts from a shortwave trough will roll through, bringing gusty winds beginning at the coast as soon as 18z on Thurs, but maintaining VFR conditions for most airports. Gusty winds will continue to strengthen as they move inland due to the tightening of pressure gradients, creating sustained winds from 8-10kt and gusting up to 20-25kt. Impact time for gusty winds affecting inland airports should be as soon as 22Z on Thurs, and calming down as early as 06Z on Fri to a sustained 5-7kt for both the inland and coastal airports. VFR conditions should persist throughout the area, with exception of MVFR CIGS making a return to KAST as the wind calms around 06z following the gusty conditions. *KTTD ASOS is currently out of commission except for altimeter, and is to be AMD not SKED. *KVUO is only accessible by dial in. PDX AND APPROACHES...VFR conditions continue throughout the TAF period with the only foreseeable impact being wind gusts beginning at about 00z on Fri. Sustained winds from the northwest around 10-15 kt will gust up to 25kt. Gusty conditions should subside by about 06- 08z on Fri. -Ruhl && .MARINE...Northwesterly onshore flow will continue as surface high pressure remains centered over the northeast Pacific. Winds generally 10-15 kt with gusts to 20 kt, increasing Thursday evening to 15-20 kt with gusts to 25 kt as a disturbance passes overhead. Seas are expected to remain steep at around 7 feet at 8 to 9 seconds. The Small Craft Advisory has been extended into Thursday night as steep seas persist and wind gusts to 25 kt will be possible. Will note that conditions are marginal so conditions may not be met at times. -Batz && .PQR WATCHES/WARNINGS/ADVISORIES... OR...None. WA...None. PZ...Small Craft Advisory until 5 AM PDT Friday for PZZ271>273. && $$ www.weather.gov/portland Interact with us via social media: www.facebook.com/NWSPortland x.com/NWSPortland