Area Forecast Discussion
Issued by NWS Pendleton, OR
Issued by NWS Pendleton, OR
169 FXUS66 KPDT 051704 AFDPDT Area Forecast Discussion National Weather Service Pendleton OR 1004 AM PDT Thu Jun 5 2025 Updated Aviation Discussion .AVIATION...18z TAFs...VFR conditions expected. Clear skies and light northerly winds will prevail at most sites, except for DLS, BDN, RDM which will see locally breezy winds at times this afternoon with gusts up to 20 kts. High clouds are then expected to build in overnight tonight. Evans/74 && 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 85 55 90 58 / 0 0 0 0 ALW 84 59 88 62 / 0 0 0 0 PSC 88 56 94 59 / 0 0 0 0 YKM 87 59 93 59 / 0 0 0 0 HRI 88 55 93 59 / 0 0 0 0 ELN 86 58 88 58 / 0 0 0 0 RDM 81 45 87 49 / 0 0 0 0 LGD 79 51 84 54 / 0 0 0 0 GCD 80 49 85 53 / 0 0 0 0 DLS 87 60 90 60 / 0 0 0 0 && .PDT WATCHES/WARNINGS/ADVISORIES... OR...None. WA...None. && $$ SHORT TERM...77 LONG TERM....77 AVIATION...74