Area Forecast Discussion
Issued by NWS Pendleton, OR
Issued by NWS Pendleton, OR
981 FXUS66 KPDT 040537 AFDPDT Area Forecast Discussion National Weather Service Pendleton OR 1037 PM PDT Thu Jul 3 2025 Updated Aviation Discussion .AVIATION...06Z TAFs...VFR with occasional MVFR conditions to prevail through the period. Remnant showers from earlier thunderstorms are currently impacting sites RDM/BDN, but are expected to clear out by 7Z. Tonight, shower/thunderstorm activity will redevelop across central and southeastern OR, then will propagate north throughout the morning and afternoon, but will be isolated to scattered. This has resulted in PROB30 groups for TSRA/SHRA being included at sites RDM/BDN between 10Z-16Z and between 17Z-22Z at sites PDT/ALW. Confidence is low (10-20%) in shower/thunderstorm activity impacting the remaining sites. However, cannot rule out gusty outflow winds impacting site PSC in the late afternoon. Otherwise, winds will mostly be 12kts or less...except at site DLS where winds 12-20kts with gusts to around 25kts will prevail through the period. Lawhorn/82 PREV DISCUSSION... /issued 206 PM PDT Thu Jul 3 2025/ .SHORT TERM...This evening through Saturday. Two distinct circulations are evident on satellite imagery this afternoon; the first is located off the southwest Oregon and northwest California coast, and the second is upstream in the northeast Pacific. These two lows are expected (>95% chance) to move onshore tonight through Friday night and facilitate widespread chances of precipitation. While the best chances (50-75%) of showers will remain over central Oregon and the Blue Mountains, low (15-40%) chances will encompass the rest of the forecast area. A chance (25+%) of thunderstorms is forecast over central Oregon and the Blue Mountains tonight through Friday evening, with the most robust convection anticipated Friday afternoon along the southern part of our forecast area in Deschutes, Crook, and Grant counties. Thunderstorms will be capable of producing small hail, locally heavy downpours, and strong outflow winds in excess of 50 mph. Drier conditions are forecast by Saturday as the low exits to the east and a drier zonal flow moves overhead. Plunkett/86 .LONG TERM...Sunday through Wednesday...Confidence is increasing in warm to hot weather Monday through Wednesday as an upper-level ridge of high pressure builds over the Pacific Northwest. While ensemble clusters depict small differences in the 500-hPa height field over the region, roughly 80% of members show a robust ridge overhead. Forecast HeatRisk peaks at Moderate (level 2 of 4) to Major (level 3 of 4) for the lower elevations, and would support some form of heat highlights. Ensemble NWP is less confident in pattern details Tuesday through Thursday. While most members show a vorticity maximum diving southeast from the Gulf of Alaska and developing into a closed low off the northern California coast Sunday through Monday, its track as it rides over the ridge and moves onshore sometime between Tuesday and Wednesday will modulate shower and thunderstorms chances. Probabilities of showers and thunderstorms are currently too low (<10%) to have in the forecast. Plunkett/86 .FIRE WEATHER...Locally breezy westerly winds in tandem with low relative humidity in the Eastern Columbia Gorge, Kittitas Valley, and portions of the Columbia Basin today are producing some locally elevated fire weather concerns; while conditions may locally meet Red Flag criteria, conditions are not expected to be widespread enough to warrant any Red Flag Warnings. Tonight through Friday, a weather system will usher in widespread precipitation chances; a chance of thunderstorms is forecast for central Oregon and the Blue Mountains. Thunderstorms will be mostly dry this afternoon and evening, but are expected to be mostly wet tonight and Friday so no Red Flag Warnings have been issued. Thunderstorms will be capable of producing strong, gusty outflow in excess of 50 mph across southeast Deschutes, Crook, and Grant counties. Plunkett/86 && .PRELIMINARY POINT TEMPS/POPS... PDT 58 77 57 87 / 0 30 20 0 ALW 61 77 61 85 / 0 30 20 0 PSC 58 82 59 89 / 0 20 20 0 YKM 57 83 57 88 / 0 20 0 0 HRI 59 80 59 89 / 0 20 20 0 ELN 56 83 56 86 / 0 10 0 0 RDM 50 74 43 82 / 30 40 20 0 LGD 56 74 52 82 / 10 50 20 0 GCD 55 76 48 83 / 30 70 40 0 DLS 60 78 57 85 / 10 20 0 0 && .PDT WATCHES/WARNINGS/ADVISORIES... OR...None. WA...None. && $$ SHORT TERM...86 LONG TERM....86 AVIATION...82