


Area Forecast Discussion
Issued by NWS Portland, OR
Issued by NWS Portland, OR
979 FXUS66 KPQR 101036 AFDPQR Area Forecast Discussion National Weather Service Portland OR 336 AM PDT Thu Jul 10 2025 .SYNOPSIS... Dry with seasonable temperatures for interior valleys this afternoon. High pressure builds Friday into the weekend, leading to much warmer temperatures. Increasing potential for triple digits inland next Tue/Wed. && .SHORT TERM...Now through Friday night...Expect another day with near normal temps as weak troughing remains in place across the PacNW. The day will start out party to mostly cloudy, clearing through the day. Highs in the upper 70s to low 80s expected inland with low to mid 60s expected along the coast. Friday will see temps jump 8-12 degrees for most inland locations as high pressure builds across the northeast Pacific along with thermally induced low pressure over the Willamette Valley. Highs in the upper 80s to around 90 degrees expected inland while the coast warms a few degrees into the mid 60s to low 70s. -Batz .LONG TERM...Saturday through Tuesday...For the weekend, the heat is on. WPC 500 mb cluster guidance continues to show very good agreement as a ridge of high pressure building and strengthening over the Eastern Pacific and Pac NW through at least early next week. There are some slight variations in exact strength and placement of the ridge over the region, but a prolonged period of upper 80s to low 90s throughout the Willamette Valley look good. There is also a decent chance (30-70%) for widespread triple digits throughout the Willamette Vally and interior lowlands next Tuesday and Wednesday. Probabilities for highs to reach 95 or greater from Salem to Eugene on Saturday are 30-50%, on Sunday it is 70-90% and on Monday it is 30-50%. Probabilities around the Portland/Vancouver Metro on Saturday are 10%, on Sunday 30-50% and Monday to 10-20%. At this time, HeatRisk is expected to remain moderate through Monday. There is a slim chance (around 10%) for a few locations in the central and southern Willamette Valley to reach 100 Sunday and Monday. Chances for triple digits increase dramatically Tuesday and Wednesday as the ridge strengthens. Probabilities for highs to reach 100 or greater for various locations in our Forecast Area on Tuesday and Wednesday (7/15/2025, 7/16/25): Portland/Vancouver Metro: 30-60%, 50-80% Salem: 60-70%, 50-70% Eugene: 50-70%, ~50% Battle Ground: 30-40%, 40-50% Kelso/Longview: 15-30%, 30-40% Astoria: less than 1% both days Hood River: 15-30% both days Newport: less than 1% both days Oakridge: 5-10% both days Temps have trended toward the upper 90s to low 100s for Tuesday and Wednesday, pushing HeatRisk values to Major for portions of the Willamette Valley and Columbia River Gorge. In addition to the upper level high pressure, models are also showing the development of a thermally induced trough slowly spreading northward into the Willamette Valley towards the start of next week. If this solution within the models does manifest, then will likely result in offshore flow. Lastly, expect most of the area to remain dry through the end of the long term IE no precipitation in the forecast at this time. However, models are hinting at a possible pattern change come Wednesday/Thursday and that could bring some very light precipitation into the forecast, but model probabilities are too low to warrant inclusion of any precipitation in the forecast for now, but will continue to monitor as models start to better resolve this feature in the coming days. -Batz/42 && .AVIATION...Marine stratus developing at the coast and off the western slopes of the Cascades, allowing for LIFR cigs at the coast southwards from KTMK, and MVFR stratus for the eastern Willamette Valley. These conditions continue until around 18-20z Thu, with some improvement to IFR/MVFR at the coast and VFR inland. Winds currently fairly weak, variable under 5 kts, but northerly winds pick up from 18z Thu onwards. Gusts up to 20 kts possible at all terminals. Westerly flow continues across NW Oregon and SW Washington, becoming northerly after 16z Thu. IFR/LIFR conditions expected along the coast with cigs around FL003-FL009 and vsbys bouncing between 1/4 SM and 2 SM. Conditions are expected to improve to MVFR/VFR north of KTMK between 07-10z Thu and south of KTMK between 10-14z Thu. For inland locations, the onshore flow is causing stratus to form on the western banks of the Cascades as of 04z Thu. This stratus is expected to slowly backfill west into the Willamette Valley, though guidance is uncertain on how far stratus could spread. Most terminals could see a couple of hours of MVFR cigs at some point, though terminals in the central Willamette Valley such as KUAO and KSLE have higher probabilities (70-80%) of MVFR cigs. Expect inland locations to recover to VFR by 16-19z Thu. PDX AND APPROACHES...VFR conditions through the majority of the TAF period. There`s a 30-60% chance of MVFR cigs between 10-15z Thu. Winds out of the north/northwest at less than 10 kt. -JLui && .MARINE...Due to upwelling, significant marine fog has developed throughout all waters. This will result in visibilities across all waters likely falling below 1 NM or less tonight through tomorrow morning. Dense Fog Advisory has been issued through 11am Thu. A weak frontal passage late tonight/early Thursday will bring about a brief southerly wind shift the rest of tonight. North/northwest winds will return across all waters by late Thursday morning and persist through the weekend as a broad area of high pressure and a thermally induced trough spreads northward. As the high pressure and associated thermally induced trough mature, expect gusty northerly winds and choppier wind driven seas, particularly south of Cape Falcon. Winds and seas will be strongest off the central coast of Oregon and will typically peak in the afternoon and evening hours over the inner waters each day through the weekend. /42 && .PQR WATCHES/WARNINGS/ADVISORIES... OR...None. WA...None. PZ...Dense Fog Advisory until 11 AM PDT this morning for PZZ210- 251>253-271>273. && $$ www.weather.gov/portland Interact with us via social media: www.facebook.com/NWSPortland x.com/NWSPortland