Area Forecast Discussion
Issued by NWS Pendleton, OR
Issued by NWS Pendleton, OR
214 FXUS66 KPDT 282330 AFDPDT Area Forecast Discussion National Weather Service Pendleton OR 430 PM PDT Thu Aug 28 2025 .UPDATED AVIATION DISCUSSION... .AVIATION...00Z TAFs...VFR conditions prevail through the TAF period with generally light winds. Feaster/97 && .PREV DISCUSSION... /issued 102 PM PDT Thu Aug 28 2025/ .DISCUSSION... The upper low over the Pacific Northwest will be displaced northward as high pressure builds over the region. Temperatures will warm Friday and Saturday as a result. Then, a large low off the coast will make its closest approach Sunday into Monday and bring a weak cold front trough. Temperatures will be slightly cooler Sunday and Monday. The high pressure will then re- establish itself for much of the upcoming week, bringing dry weather and unseasonably warm temperatures. For the remainder of today, with the upper low in place, there remains the potential for showers and thunderstorms, mainly over the Washington Cascades and eastern Oregon mountains. Overall chances are low (<20%). There is even a smaller chance on Friday, mainly over eastern Oregon. After that, it will be dry through Labor Day weekend and into next week. High temperatures will be 10 to 15 degrees above normal Friday and Saturday and even possibly as much as 20 degrees above normal in some locations by midweek. HeatRisk will be Moderate across most of the lower elevation areas Friday and Saturday and then by Tuesday and Wednesday, there will be widespread Moderate HeatRisk, with Major HeatRisk moving into places such as the Columbia Basin, Yakima and Kittitas Valleys. Highs in the mid to upper 90s are being forecast, with the caveats that cloud cover can impact high temperatures coupled with the much shorter daylight in early September. By the middle of next week, the ECMWF EFI shows anomalies of 0.9+ across the Columbia Basin for high temperatures and 0.8+ for low temperatures. As we move into September, but average highs and lows are decreasing (with highs in the low to mid 80s across the region), so high temperatures in the mid to upper 90s and possibly hitting triple digits in the Basin would be easily 10 to 15 and possibly hitting 20 degrees above average in some areas. That is the main reason the anomalies are so large, as evidenced by the ECMWF EFI. && .PRELIMINARY POINT TEMPS/POPS... PDT 61 93 62 93 / 0 0 0 0 ALW 66 94 67 94 / 0 0 0 0 PSC 61 96 61 97 / 0 0 0 0 YKM 63 94 62 94 / 20 0 0 0 HRI 62 96 63 97 / 0 0 0 0 ELN 58 92 59 93 / 30 0 0 0 RDM 51 91 53 90 / 0 0 10 0 LGD 56 91 56 92 / 10 10 0 0 GCD 56 91 56 92 / 10 10 0 0 DLS 64 96 64 93 / 0 0 0 0 && .PDT WATCHES/WARNINGS/ADVISORIES... OR...None. WA...None. && $$ DISCUSSION...77 AVIATION...97