Area Forecast Discussion
Issued by NWS Portland, OR
Issued by NWS Portland, OR
572 FXUS66 KPQR 251102 AFDPQR Area Forecast Discussion National Weather Service Portland OR 402 AM PDT Fri Jul 25 2025 .SYNOPSIS...More seasonal temps expected today through Sunday as onshore flow is enhanced by increased upper level troughing. Another warm up is expected early to mid next week, with thunderstorms looking possible along the Cascades. && .SHORT TERM...Now through Sunday Night...Little change in sensible weather across the area this morning as satellite imagery once again shows marine stratus entrenched over coastal areas and making progress into the Coast Range gaps and interior valleys of southwest Washington as of 3 AM Friday. Observational trends and latest hi-res guidance suggest cloud cover will fill into the Willamette Valley and from both the north and south around daybreak, yielding a cloudier start to the day today. In the upper levels, large scale troughing over western Canada will begin to sag southward into the region today, with gradual 500 mb height falls and decreasing 850 mb temps corresponding to more seasonable highs in the upper 70s to low 80s in the interior valleys this afternoon. Expect more of the same through the weekend as upper level troughing and onshore flow maintain temperatures near seasonal norms, with a deeper marine layer contributing to nightly stratus intrusions into the interior valleys. /CB .LONG TERM...Monday through Thursday...Monday will kick off another stretch of warmer weather as ensemble clusters show good agreement on high pressure rebuilding over the western CONUS. This will send inland high temperatures back towards 90 degrees during the first half of next week. Although hotter temperatures are expected, the potential for more significant heat related concerns remains relatively low at this time as the probability to reach 95 degrees generally stays below 20% and HeatRisk remains mainly in the minor category through the period. The other concern for next week will be thunderstorm potential as guidance continues to depict a deep upper level trough setting up over the NE Pacific and establishing southerly flow over the Pacific Northwest, helping to draw rich mid level moisture into the region. NBM guidance has started to catch onto this scenario, depicting chance to slight chance PoPs along the Cascades from Tuesday into Thursday of next week. Opted to introduce a chance of thunderstorms to match those PoPs given the potentially favorable synoptic setup. Will continue to closely monitor thunderstorm potential for next week in the coming days. /CB && .AVIATION...Currently VFR conditions at most inland locations and MVFR stratus along the coast. The coastal stratus, currently pushed up the Columbia River to KSPB and a bit into the southern edge of the Coast Range as of 10Z Friday, is expected to push into the Willamette Valley by 12Z Friday (20-30% chance of MVFR CIGs). By 18-20Z Friday, VFR returns inland as stratus clouds clear out. As for coastal terminals, KAST conditions will likely improve to VFR by 22-23Z Friday, but KONP may keep the MVFR stratus through the rest of the TAF period (30-40% chance of MVFR). Otherwise, expect northerly to northwesterly winds around 5-10 kt throughout the area, strongest in the afternoon. PDX AND APPROACHES...VFR CIGs with clear skies until 12Z Friday, then a 15-30% chance of MVFR stratus through the morning. Conditions should improve back to VFR by 18-20Z Friday. Northwesterly flow under 10 kts through the TAF period. ~Hall && .MARINE...Going through the end of the work week through the weekend high pressure will maintain north to northwesterly winds with gusts around 13-18 knots during the afternoon/evening hours each day. Background swells don`t look particularly noteworthy so seas likely remain around 3-6 ft each day into next week. Small Craft advisory conditions are unlikely this week. There will be some strong ebb currents through the Columbia River bar this morning and Saturday morning, which may lead to locally choppy seas. ~Hall/Schuldt && .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