FXUS66 KPQR 272158 AFDPQR Area Forecast Discussion National Weather Service Portland OR 258 PM PDT Mon Apr 27 2026 .SYNOPSIS...Onshore flow with heavy cloud cover and mild daytime highs through Tuesday. Drier and warmer weather returns Wednesday through the weekend as high pressure builds. Weather impacts appear minimal going forward. && .DISCUSSION...Today through Sunday night...Satellite imagery shows widespread stratus and a mesoscale low that is spinning off of the coast of Vancouver Island. This low is producing small shortwave troughs that are subsequently moving over the Pacific Northwest. Some areas of light drizzle today with these shortwaves, but the overall accumulation and impact has been minimal. Winds are fairly light and variable with a slight westerly direction. Cloud cover will persist over the next 24 hours keeping temperatures in the low to mid 60s across interior valleys and mid to upper 50s along the coast. Wednesday into Thursday high pressure rebuilds with increasing easterly flow aloft. 500 mb heights remain elevated and dry air moves into the region. Expecting temperatures to rise steadily as 850 mb temperatures increase to around 7-8 deg C. Surface temperatures will be on the warm end of seasonable with interior highs in the mid to upper 70s. On Thursday, there is around a 30-60% chance of the maximum temperature exceeding 80 degrees though HeatRisk remains minor due to cooling temperatures overnight. Friday through Saturday, most deterministic and ensemble guidance depicts the upper-level ridge flattening as a weak trough moves into the Pacific Northwest from Canada. It appears that there is limited moisture with this trough, so precipitation chances remain around 20-40% across the Cascades and less than 10% elsewhere. In addition, most ensemble members maintain above-average 500 mb heights over the area, meaning seasonably warm temperatures would continue through the end of the week with high temperatures forecast in the 70s for interior valleys. By Sunday, the majority of ensemble members have the trough moving southward toward California while upper-level ridging re-builds over the Pacific Northwest. Even this far out, NBM guidance is already suggesting higher confidence (70-90% chance) that temperatures exceed 80 degrees along the I-5 corridor on Sunday with the highest probabilities near the Portland-Vancouver Metro area. -27/10 && .AVIATION...Satellite imagery shows widespread dense stratus over the region that has been more stubborn to dissipate. A weak disturbance will move over the Pacific Northwest today bringing around a 30-40% chance of light drizzle. During this period, expect lifting skies though will remain overcast. Overall looking at a combination of high end MVFR and low end MVFR. Winds will be less than 10 kt through the day shifting to the northwest over the next 24 hours. Within the transition period conditions will bounce between the two. KPDX AND APPROACHES...Slow improvement from MVFR to VFR today though the trend is it occurring by 20Z Mon. CIGs will linger in the 3500-4500 ft AGL range once they eventually lift. While there will be some moisture in the air from the passing disturbance, a lack of cooling overnight will eliminate nearly any chance for fog overnight. -27 && .MARINE...Winds remain westerly to northwesterly into Tuesday with gusts expected to remain below 15-20 kts. By Tuesday evening, high pressure returns over the waters, remaining through the end of the week. Winds become northerly with a 70-90% chance for at least isolated small craft northerly wind gusts up to 20-25 kt from Wednesday through Friday. Gusts will be strongest each late afternoon and evening hours when pressure gradients are tightest. Seas of 6-7 ft persist through the week with a northwesterly swell. Minimal marine concerns moving forward. -27/10 && .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