Area Forecast Discussion
Issued by NWS Pendleton, OR
Issued by NWS Pendleton, OR
394 FXUS66 KPDT 050520 AFDPDT Area Forecast Discussion National Weather Service Pendleton OR 1020 PM PDT Wed Jun 4 2025 .UPDATED AVIATION...06Z TAFs...VFR conditions will persist through the forecast period. CIGs will remain mostly SKC with a few sites seeing SCR-FEW 25 kft. Winds will be mostly diurnally driven and variable below 6 kts with DLS remaining near 10 kts through 20Z. Bennese/90 && .PREV DISCUSSION... /issued 421 PM PDT Wed Jun 4 2025/ SHORT TERM... Tonight through Saturday...Dry north to northwesterly flow will continue through Friday. Then an upper level ridge will begin to build over the region on Saturday. Temperatures will warm through the period. Highs will start about 5 degrees above normal on Thursday and mainly be in the 80s, and end about 15 to 20 degrees above normal on Saturday and be in the 90s. By Friday into Saturday, HeatRisk will reach the moderate category. On Friday the moderate will mainly be confined to the Columbia Basin, Yakima Valley and surrounding areas. On Saturday, the Moderate HeatRisk will overspread much of the lower elevations of the region. Diurnal breezes in the 15 to 20 mph range are expected each day. LONG TERM... Saturday night through Wednesday...The ridge will move over the Pacific Northwest Sunday and Monday and this will build the heat. There is some uncertainty as to how quickly the ridge breaks down, but by midweek, temperatures do look to be back into the 80s to lower 90s. However, in the meantime, an early season heat wave will occur and we are looking at the potential of 5 to 6 days of 90s in many lower elevations and mid 90s in many areas with the Columbia Basin topping out in the triple digits (40-60%) confidence at this point). Sunday and Monday also will have major HeatRisk across the Columbia Basin, Yakima Valley and portions of the Blue Mountain Foothills and moderate HeatRisk over all but the highest elevations. 80 to 90% of the ECMWF ensemble members have 100+ temperatures for Tri-Cities for Sunday and Monday and about 40% of the members linger the triple digits into Tuesday. The ECMWF EFI is showing 0.8 to 0.9 anomalies for high and low temperatures both Sunday and Monday for a broad area of Northeastern Oregon and Southeastern Washington. && .PRELIMINARY POINT TEMPS/POPS... PDT 51 84 56 90 / 0 0 0 0 ALW 55 84 59 88 / 0 0 0 0 PSC 51 89 55 94 / 0 0 0 0 YKM 53 87 58 93 / 0 0 0 0 HRI 51 88 55 94 / 0 0 0 0 ELN 52 86 57 89 / 0 0 0 0 RDM 41 81 46 88 / 0 0 0 0 LGD 48 79 51 84 / 0 0 0 0 GCD 46 81 50 86 / 0 0 0 0 DLS 53 88 60 91 / 0 0 0 0 && .PDT WATCHES/WARNINGS/ADVISORIES... OR...None. WA...None. && $$ SHORT TERM...77 LONG TERM....77 AVIATION...90