FXUS66 KPQR 190505 AFDPQR Area Forecast Discussion National Weather Service Portland OR 1005 PM PDT Wed Sep 18 2024 .UPDATED AVIATION DISCUSSION... && .SYNOPSIS... High pressure returns, bringing dry weather with near to slightly below normal temperatures through the end of the week. Another front will bring a chance of showers Sunday into Monday. Warmer and drier conditions possible next week, however some uncertainty remains with the weather pattern. && .SHORT TERM...Now through Friday Night...Satellite imagery and surface weather observations as of early Wednesday afternoon depict dry conditions with lingering scattered/broken clouds as yesterday's upper level trough exits the region. As high pressure re-builds over the NE Pacific and Pacific Northwest, expect decreasing clouds through the early evening. Winds will be out of the north/northwest with the strongest gusts (up to 20 mph) through the Columbia River Gorge. High temps this afternoon will re-bound into the low to mid 70s for interior lowland valleys (slightly below normal) and mid to upper 60s along the coast. Expect dry weather with mostly sunny skies Thursday to Friday as high pressure remains over the area. Light to moderate onshore flow continues, with the strongest gusts again through the Gorge and Upper Hood River Valley area. Each night, could see some patchy fog development along with low clouds overnight into the early morning hours. Low temperatures are forecast in the 40s to mid 50s, with afternoon high temps similar to today. Overall, we'll have pleasant days to end the week. -Alviz .LONG TERM...Saturday through Wednesday...Lingering uncertainty this weekend into the early part of next week as medium and long range guidance continues to diverge with respect to how the pattern will evolve beyond Friday. That said, ensemble clusters have started to slightly favor a warmer and drier pattern for Saturday and beyond, with about two thirds of solutions now indicating a ridgier pattern while the other third still depict troughing or more zonal flow. As a result, NBM interquartile ranges for temperatures have narrowed to show inland high temperatures most likely residing in the mid to upper 70s Saturday through Monday. Precipitation chances have also gone down as models hint at upper level ridging, but NBM mean guidance still carries chance to slight chance PoPs across mainly the northern half of the area late Sunday into early Monday, which reflects the below normal forecast confidence. Model agreement actually increases towards the beginning of next week as ensemble clusters show about 90 percent of solutions favoring some degree of upper level ridging over the Pacific Northwest for Monday and Tuesday. As such, Tuesday looks to be the warmest day in the next week with highs possibly reaching into the mid 80s in the interior valleys. Models start to diverge again beyond Tuesday as guidance is split between another trough and a more gradual breakdown of the ridge. /CB && .AVIATION...Northeast flow aloft as upper ridge of high pressure gradually builds over the region headed through Thursday. Stratus has already begun to build along the coast with conditions likely (60-80%) deteriorating to IFR tonight into Thursday morning. Stratus also likely (40-80%) back-builds off the Cascade foothills towards the inland terminals after 10-12z Thursday with MVFR CIGs trending toward 1500-2000 ft - highest likelihood at PDX and TTD. Fortunately any low status inland will dissipate around midday. Generally expect north to northwest winds, increasing during the afternoon. PDX APPROACHES...Predominately VFR expected through the overnight hours as broken stratus has lifted to around FL040-050. MVFR stratus likely (70-90% chance) redevelops after 12z Thursday before breaking up around 18z. Expect northwest winds to around 6-8 kt Thursday afternoon. -Schuldt/DH && .MARINE...High pressure has returned to the coastal waters, resulting in increased northerly winds today, likely continuing through the week. Winds may gust up to 20-25 kt at times tonight, especially over the outer coastal waters. Wind gusts to 25 kt becomes more likely by Thursday afternoon as the thermal trough strengthens over the southern Oregon coast. Have issued a Small Craft Advisory to cover the increased winds and choppy seas expected through Thursday night. Pressure gradients across the coastal waters weaken somewhat over the weekend, likely resulting in a decrease in north to northwest wind speeds. A persistent northwest swell around 5 to 7 ft is expected to continue through late week. Seas around 5 to 6 ft today likely increase to around 7 to 8 ft Thursday through Friday, with a dominant period of around 8 to 9 seconds. Seas then expected to subside back to around 5 to 6 ft for the weekend. /DH && .PQR WATCHES/WARNINGS/ADVISORIES... OR...None. WA...None. PZ...Small Craft Advisory from noon to 11 PM PDT Thursday for PZZ253. Small Craft Advisory from noon Thursday to 5 AM PDT Friday for PZZ271>273. && $$ www.weather.gov/portland Interact with us via social media: www.facebook.com/NWSPortland x.com/NWSPortland