972 FNUS76 KPDT 100152 FWSPDT Spot Forecast for Big Hole Fire...US Forest Service National Weather Service Pendleton OR 652 PM PDT Tue Sep 9 2025 Forecast is based on forecast start time of 0800 PDT on September 10. ***Thunderstorms imply gusty and erratic winds*** ***Winds are 20 foot 10-minute averages*** ***CWR-Chance of wetting rain 0.10 or greater*** ***Ventilation Index is derived from the transport wind multiplied by the mixing height in 100's of feet. Index categories are a generalized indicator only.*** If you have questions or concerns with this forecast, please contact our office at (541) 276-8134. .DISCUSSION...Shower and thunderstorm chances will continue for the region as a low pressure system moves into the Pacific Northwest. Rain chances will be at their greatest during the day Wednesday, before shower chances generally start to shift eastward. Isolated storms are possible, but are expected to be wetting in nature should any occur. Winds will generally remain light out of the west-northwest over the next couple of days. .WEDNESDAY... Sky/weather.........Mostly cloudy (75-85 percent). Rain showers likely (70-80 percent) and a chance of thunderstorms (25-35 percent) throughout the day. CWR.................31 percent increasing to 70 percent late in the morning. Chance of lightning.35 percent. Max temperature.....64-67. Min humidity........59-64 percent. Wind (20 ft)........Northwest winds 5 to 8 mph. Gusty and erratic winds expected near thunderstorms. Mixing height.......2600 ft AGL. Transport winds.....North around 7 mph shifting to the West late in the afternoon. Ventilation Index...Poor (40) increasing to poor (100) in the afternoon. TIME (PDT) 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM 6PM 7PM Chc of ltng (%).10 10 10 30 30 30 40 40 40 20 20 20 Temp............45 50 55 60 63 64 64 61 64 63 63 58 RH..............99 98 84 74 66 64 64 68 64 69 65 73 20 FT wind dir..W W W NW NW NW NW NW NW W W W 20 FT wind spd..4 4 4 4 4 4 5 5 5 5 5 5 20 FT wind gust.6 6 6 8 8 8 10 10 10 10 10 10 .WEDNESDAY NIGHT... Sky/weather.........Mostly cloudy (80-90 percent). Rain showers likely (60-70 percent) with a slight chance of thunderstorms (15-25 percent) early in the evening, then chance of showers (35- 45 percent) overnight. CWR.................70 percent decreasing to 8 percent. Chance of lightning.22 percent. Min temperature.....40-43. Max humidity........95-100 percent. Wind (20 ft)........West-Northwest winds 5 to 8 mph. Gusty and erratic winds expected near thunderstorms. Mixing height.......500 ft AGL. Transport winds.....West-Northwest 5 to 12 mph. Ventilation Index...Poor (130) decreasing to poor (60) overnight. .THURSDAY... Sky/weather.........Mostly cloudy (65-75 percent). Chance of showers (45-55 percent) with a slight chance of thunderstorms (15-25 percent). CWR.................8 percent increasing to 43 percent late in the morning, then decreasing to 3 percent late in the afternoon. Chance of lightning.29 percent. Max temperature.....66-69. Min humidity........51-56 percent. Wind (20 ft)........Northwest winds 5 to 8 mph. Gusty and erratic winds expected near thunderstorms. Mixing height.......3400 ft AGL. Transport winds.....Northwest 9 to 13 mph. Ventilation Index...Poor (90) increasing to fair (300) in the afternoon. $$ Forecaster...Evans Requested by...Ella Nichols Type of request...WILDFIRE .TAG 2521684.0/PDT .DELDT 09/10/25 .FormatterVersion 2.0.0 .EMAIL ella.nichols12@gmail.com,thomas.alvut@usda.gov