Area Forecast Discussion
Issued by NWS Portland, OR
Issued by NWS Portland, OR
126 FXUS66 KPQR 300537 AAA AFDPQR Area Forecast Discussion...UPDATED National Weather Service Portland OR 937 PM PST Sat Nov 29 2025 Updated aviation discussion. .SYNOPSIS...High pressure over the area will persist through Sunday with a weak shortwave trough pushing southeast along the northern edge this evening. Will see a quick shot of rain overnight but it is not expected to widespread, and accumulations will be light. Settled weather on Sunday and Monday with cooler temperatures Monday morning. The next period of active weather starts Tuesday through the end of the week with round after round of precipitation associated with warm fronts. && .SHORT TERM...Now through Monday Night...Minimal changes to the forecast today due to a fairly persistent pattern. Climatologically abnormal, high pressure lingers over the area keeping skies clear, dry, and slightly cooler. The high pressure ridge will remain in the general area through Monday morning though this evening a shortwave ridge will pass through the flow. This shortwave will increase mixing and bring an influx of moisture to the area. There is around a 30-40% chance of rain through Sunday morning, though that is assuming the lower elevations of the atmosphere are moist enough for the precipitation to reach the ground. Overall, even if it does rain no impacts are expected. Dry conditions persist through Monday with mostly clear skies. Winds will be lightly easterly as well which will bring in slightly cooler air. With the clear skies and presence of cooler air, expecting overnight temperatures to drop Sunday night into Monday morning. Widespread minimum temperatures less than 35 degrees are expected inland, with lows in the 40s along the coast. Probabilistically there remains a spread with the 10th percentile (coldest solution) around 25-30 degrees in Eugene and Corvallis, 32 degrees in Portland and along the coast, and slightly colder in the Upper Hood River Valley and northern Clark County. Overall, the outer rural areas have a higher probability of freezing temperatures. These lows will quickly rebound though through the day. Widespread frost is possible in the interior lowlands which could accumulate on some metal surfaces. Fog is more likely to the south where there is a 50% chance of dense fog around Eugene. Clouds will fill in through the afternoon as a warm front shifts towards the area. The warm front is not overly robust and precipitation amounts have decreased over the last several days. .LONG TERM...Tuesday through Saturday...Rain will persist through the day but will be light. Based on forecast soundings, the rain could trend more towards drizzle with a very deep cloud layer. Accumulation wise will see very little 24-hr rainfall totals ending at 4 PM Tuesday range from 0.05-0.2 inch with the highest accumulation along the coast and Cascades. there is a 10% chance of nearly no accumulating rain, and a 10% chance of 0.15-0.2 inch in the valley, and 0.2-0.3 inch along the coast. Snow levels will be high. Wednesday and Thursday will be fairly benign with no precipitation expected as high pressure builds once again. There is good agreement in the ensembles regarding this pattern. The next major weather shift comes on Friday into Saturday. At this point models are not in agreement with nearly half showing heavy rain and others showing very little. 24 hr rainfall totals on Saturday afternoon will be around a quarter of an inch inland, a half inch along the coast and slightly higher accumulation in southwest Washington. If we want to dive into the higher end amounts (90th percentile), there is quite the range. The NBM 90th percentile is showing the 24 hour accumulation ranging from 0.6 inch in the southern Willamette Valley to 0.75 in the northern. Nearly an inch in Longview and 1.25 inch along the south Washington coast. Ultimately the amount of rain will be decided upon by where the incoming low and associated warm front align. Will note that river forecasts are showing forecast rises on many area rivers on Saturday. The thing to note, and this has been the scenario almost all season, is that these systems tend to see the low pressure systems filling and thus become less intense. -27 && .AVIATION...At 0530z Sunday, satellite and surface weather observations depicted overcast skies across northwest OR and southwest WA, with MVFR cigs at the coast and at KSLE and KEUG, with low-end VFR cigs around 4000 ft north of KSLE. Expect this trend to continue with VFR cigs to the north and MVFR cigs to the south. Cigs should lift to VFR at KSLE and KEUG Sunday morning around 14z at KSLE first and around 18-19z at KEUG. After 19z Sunday, expect mostly clear skies aside from scattered thin high clouds, resulting in VFR flight conditions at all terminals Sunday afternoon and evening. Winds will remain relatively light, except at KTTD where easterly winds will continue around 10-13 kt and at KPDX where east to east-southeast winds around 5-7 kt continue. There will also be a few spotty light rain showers near KONP and KEUG Saturday night, however these showers will result in little to no impacts aside from brief visibility reductions as low as 3-6 SM. KPDX AND APPROACHES...Expect VFR flight conditions throughout the 06z TAF period with east to east-southeast winds around 5-7 kt. -23 && .MARINE...Benign weather continues across the waters as a weak low drops south along the coast tonight. Winds will remain less than 10 kt while onshore flow turns offshore again and seas hold fairly steady at 4-8 ft. High pressure building offshore into next week will then see winds hold at 5-10 kt out of the north to northeast through Monday night. Another boundary crossing the waters will see winds build to 15-20 kt out of the northwest while a long-period swell will push seas toward 10 ft on Tuesday. Winds and seas then ease midweek with another weather system potentially arriving late in the week. -36 && .BEACH HAZARDS...A long-period westerly swell is expected along the northwestern Oregon and southwestern Washington coasts from late Monday through Wednesday next week. Wave heights increasing to 8 to 10 ft on Tuesday may not appear to present a safety risk to those on area beaches, but these energetic waves will present a moderate to high risk for sneaker waves, waves which can run significantly farther up a beach than normal, including over rocks and jetties. In addition, a period of perigean spring or "king" tides means these waves will have an even easier time reaching high up onto beaches, limiting the areas which may be safe from wave action. A Beach Hazards Statement has therefore been issued from 7 AM Tuesday to 10 PM Wednesday. Sneaker waves can create potentially life-threatening conditions in the surf zone when beachgoers can be unexpectedly knocked off their feet and pulled out into cold ocean waters. Caution should be used when in or near the water, and those with children should be especially watchful. Never turn your back on the ocean, and be sure to keep an eye on the waves. Those participating in razor clam digs should additionally exercise caution. -36 && .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