FXUS66 KPQR 190452 AAA AFDPQR Area Forecast Discussion...UPDATED National Weather Service Portland OR 952 PM PDT Thu Apr 18 2024 Updated aviation discussion... .SYNOPSIS... High pressure over the region will remain through Friday, maintaining mild sunny days and cool clear nights. Offshore flow continues, with breezy easterly winds on the west slopes of the Cascades and to some degree, the Coast Range. Will return to cooler conditions this weekend, as a front pushes across the region. Unsettled weather continues into early next week. && .SHORT TERM...TODAY THROUGH SATURDAY...High pressure continues in the region, with sunny and warm conditions. Temperatures today are on track to reach right about to 70 or just barely into the low 70s throughout the Willamette Valley, while the coast will be just a bit cooler, peaking in the upper 60s. Offshore flow continues, with generally NE winds curling N in the central and southern Willamette Valley. Generally pleasant spring conditions expected today and tomorrow. Breezy east winds through the Gorge are currently gusting to around 25mph, but this is expected to continue increasing through tonight and Friday as the thermal trough continues building. High temperatures Friday will be just a degree or two warmer, and east wind through the Gorge will increase late Thursday night/early Friday morning. Exposed upper elevation areas could see gusts potentially up to 35-50mph throughout most of Friday, gradually weakening over Friday night. The rest of the region should see NE or E breezy winds up to 10-20 mph. Will see wind-reversal along the coast in the afternoon, with east to northeast winds becoming southerly to south of Florence in the afternoon, and as far north as Newport by sunset as the thermal trough shifts inland over the Coast Range. This will allow for cooler ocean air to spread back across the coastal zones at that time. But, offshore flow persists on to the north overnight, such as at Astoria. Likely be one of those afternoons where Newport is 59 with light south wind and Astoria is around 70 with an east wind in the late afternoon. Changes gradually arrive Fri night into early Sat, as a front well offshore approaches. Will see offshore flow gradually weaken Fri night, with increasing clouds later Fri night into Sat am. Timing still suggest showers or pockets of light rain spreading to the coast by midday Sat, and pushing inland during the afternoon. Again, not a strong front, as rainfall expected on Sat being 0.10 to 0.25 inch along the coast/coastal mountains, and 0.02 to 0.10 for lowlands form Cowlitz Valley through the Willamette Valley. Will be much cooler on Saturday, thanks to clouds and onshore flow. Highs only in the 50s along the coast, and lower to middle 60s inland. /Rockey/JLiu .LONG TERM...SUNDAY THROUGH WEDNESDAY...Onshore flow begins developing Saturday night into Sunday. Cooler conditions are expected Sunday as a result, with coastal highs in the mid 50s, and right around 60 inland. Ensemble guidance points towards a brief shortwave ridge impacting the area on Monday and Tuesday morning, allowing for warmer temperatures potentially back into the 70s. Tuesday and Wednesday see potential for another front, allowing for light showers and cooler temperatures again. /JLiu && .AVIATION...VFR thresholds with clear skies prevail at all terminals through the entire TAF period as high pressure remains aloft. Winds tonight will generally be easterly and around 5-10 kt, except in the central/south Willamette Valley where winds will be more northerly. Inland locations could see isolated gusts up to 18-20 kt through 15-16z Fri. Easterly/northeasterly winds continue Friday as surface high pressure remains settled east of the Cascades. East winds will strengthen after 15-16z Fri as KTTD-KDLS pressure gradients tighten slightly. The strongest winds will be through the Columbia River Gorge into the Portland Metro Area, where east winds could gust up to 25-30 kt through 00-02z Sat. Friday evening, winds will begin to weaken. PDX AND APPROACHES...VFR thresholds under clear skies through the entire TAF period. East winds will be around 12-15 kt tonight, strengthening after 15-17z Fri to around 18-22 kt with gusts up to 25-30 kt through 00-02z Sat. Winds begin to weaken in the evening. -Alviz && .MARINE...A thermal trough continues to build over the western Oregon coast this afternoon with high pressure off the WA/B.C. coast. This has caused a tightening of surface pressure gradients, which will bring elevated wind gusts to 25-30 mph through this evening, resulting in choppy waters. A Small Craft Advisory remains in effect through this evening. Pressure gradients will weaken tonight as the thermal trough continues to build north along the Oregon Coast, causing winds to weaken. This pattern will continue through Friday until a Pacific front approaches the waters Friday night, breaking down the thermal trough and turning winds southerly. Southerly winds increase through the day Saturday as the front moves through the waters, with Small Craft winds likely into Sunday. General seas through Saturday afternoon of 4 to 7 feet at 15 to 17 seconds, consisting of a long period southwest swell. Swell becomes westerly Saturday evening into Sunday, increasing general seas to 9 to 11 feet at 9 to 11 seconds. -HEC && .PQR WATCHES/WARNINGS/ADVISORIES... OR...None. WA...None. PZ...Small Craft Advisory until 11 PM PDT this evening for PZZ252-253- 272-273. && $$ www.weather.gov/portland Interact with us via social media: www.facebook.com/NWSPortland www.twitter.com/NWSPortland