Area Forecast Discussion
Issued by NWS Pendleton, OR
Issued by NWS Pendleton, OR
127 FXUS66 KPDT 302025 AFDPDT Area Forecast Discussion National Weather Service Pendleton OR 125 PM PDT Sat Aug 30 2025 .DISCUSSION...A relatively complex synoptic pattern is setting up for the Pacific Northwest for the next week. Satellite imagery currently shows a broad low pressure system circulating just off the coast. Models have this low meandering towards the Olympic Peninsula before retrograding during the week, leaving our forecast area caught between two deep troughs. A quasi-ridge pattern results, which will cause a distinct warm-up through the midweek. So long as this offshore low remains in our area of influence, however, expect mild gap flows and persistent chances for isolated showers and thunderstorms over at least the next several days. Currently, radar shows some light shower and storm activity developing across Union and Wallowa County. CAMs are not too bullish on coverage this afternoon and evening, likely due to the low shear and subsidence aloft as weak ridging forms ahead of this offshore low, but the ingredients still remain for at least isolated activity for the area. Winds remain relatively light, however gap flows are picking up above guidance for The Dalles this afternoon, suggesting a stronger cross-Cascade gradient than what models are picking up on (which makes sense. There is a low offshore after all). Expect mild breezes downslope of the Cascades this afternoon as well as tomorrow, combining with low RHs to make for elevated fire weather concerns. Don`t think winds will be strong nor widespread enough to warrant any headlines, but active incidents (like the Flat Fire) will certainly be affected by these conditions. Favorable ascent then shifts to the central Washington Cascades for tomorrow, albeit only enough to support slight (15-20%) chances for showers and thunderstorms. Focus then shifts to the building heat beyond Labor Day, but before then, this low looks to circulate a secondary trough from SoCal into the region Tuesday night into Wednesday. Models aren`t depicting this system too cleanly as of yet, but will certainly be something to keep an eye on as the days progress. By then, the heat will really start ramping up, with decent probabilities (50-60%) for the lower Columbia Basin to see high temps eclipse 100 degrees, which would flirt with daily records given the time of year. Evans/74 && .AVIATION...18z TAFs (Previous Discussion)...Expecting primarily VFR conditions with light, terrain-driven winds less than 12 kts and mid- level cigs slowly building over the course of the period, becoming sct-bkn 10-15 kft by the evening. Areas of smoke and haze will obscure the horizon at some sites, while MVFR conditions may occur (40-50%) at times this morning at BDN/RDM due to smoke from area wildfires. Evans/74 && .PRELIMINARY POINT TEMPS/POPS... PDT 63 94 61 94 / 0 0 10 0 ALW 68 97 68 97 / 0 0 10 0 PSC 62 97 62 96 / 0 0 10 0 YKM 63 95 63 95 / 10 10 10 0 HRI 62 96 63 96 / 0 0 10 0 ELN 58 94 60 93 / 10 10 20 0 RDM 51 92 50 93 / 10 0 0 0 LGD 60 94 60 96 / 10 0 0 0 GCD 61 95 60 97 / 0 0 10 0 DLS 63 92 63 94 / 10 0 10 0 && .PDT WATCHES/WARNINGS/ADVISORIES... OR...None. WA...None. && $$ SHORT TERM...74 LONG TERM....74 AVIATION...74