233 FNUS76 KPDT 090224 FWSPDT Spot Forecast for STONE...high dessert team 3 National Weather Service Pendleton OR 724 PM PDT Mon Sep 8 2025 Forecast is based on forecast start time of 2000 PDT on September 08. ***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...Slight chance of showers and thunderstorms will taper off tonight. Cooler and cloudy conditions continue through tonight. Another round of showers and thunderstorms are expected Tuesday afternoon and early evening. Gusty winds, small hail, and brief downpours will be the main threats. Locally wetting rains are possible. With clouds and moisture around, expect good RH recoveries overnight, with minimum RHs during the day in the 40 to 50 percent range on Tuesday. Surface winds will be from the west/northwest, with southerly flow aloft. .REST OF TONIGHT... Sky/weather.........Partly cloudy (30-40 percent) then becoming mostly cloudy (55-65 percent). Chance for showers and isolated thunderstorms in the early evening. CWR.................4 percent. Chance of lightning.11 percent. Min temperature.....51-54. Max humidity........85-90 percent. Wind (20 ft)........West winds 5 to 7 mph early in the evening becoming light. Ridgetop wind.......South around 10 mph. Mixing height.......500 ft AGL. Transport winds.....West 5 to 14 mph. Ventilation Index...Poor (140) decreasing to poor (30) overnight. TIME (PDT) 8 PM 10 PM MIDNGT 2 AM 4 AM 6 AM Chc of ltng (%).10 10 0 0 0 10 Temp............67 62 57 56 54 51 RH..............55 66 75 78 82 90 20 ft wind......W 5 W 5 W 5 SW 4 SW 4 SW 4 20 ft wind gust.7 7 7 5 5 .TUESDAY... Sky/weather.........Partly sunny (55-65 percent). Chances of showers throughout the day, with thunderstorms possible in the afternoon. CWR.................8 percent increasing to 25 percent late in the afternoon. Chance of lightning.25 percent. Max temperature.....72-75. Min humidity........40-50 percent. Wind (20 ft)........Light winds becoming northwest 5 to 7 mph late in the afternoon. Gusty and erratic winds expected near thunderstorms. Ridgetop wind.......South around 10 mph. Mixing height.......5200 ft AGL. Transport winds.....Northwest 5 to 7 mph shifting to the north around 8 mph late in the afternoon. Ventilation Index...Poor (50) increasing to fair (230) in the afternoon. .TUESDAY NIGHT... Sky/weather.........Mostly cloudy (50-70 percent). Slight chance of thunderstorms in the evening. Chance of rain showers through the night. CWR.................25 percent decreasing to 4 percent late in the evening. Chance of lightning.19 percent. Min temperature.....51-54. Max humidity........87-92 percent. Wind (20 ft)........Northwest winds 5 to 7 mph early in the evening becoming light. Gusty and erratic winds expected near thunderstorms. Ridgetop wind.......South around 5 mph. Mixing height.......900 ft AGL in the evening then 500 ft AGL overnight. Transport winds.....North 5 to 8 mph shifting to the northwest around 5 mph overnight. Ventilation Index...Poor (90) decreasing to poor (30) overnight. .WEDNESDAY... Sky/weather.........Mostly cloudy (70-80 percent). Slight chance of thunderstorms in the morning. Rain showers likely through the day. Chance of thunderstorms in the afternoon. CWR.................4 percent increasing to 71 percent late in the morning. Chance of lightning.25 percent. Max temperature.....Around 70. Min humidity........61-66 percent. Wind (20 ft)........Light winds becoming northwest 5 to 7 mph. Gusty and erratic winds expected near thunderstorms late in the morning. Gusty and erratic winds expected near thunderstorms late in the afternoon. Ridgetop wind.......South 5 to 10 mph. Mixing height.......3300 ft AGL early in the morning. Transport winds.....Northwest 5 to 6 mph shifting to the north 8 to 9 mph late in the morning. Ventilation Index...Poor (30) increasing to fair (270) in the afternoon. $$ Forecaster...NWS Seattle Requested by...chistoph Type of request...WILDFIRE .TAG 2521348.4/PDT .DELDT 09/08/25 .FormatterVersion 2.0.0 .EMAIL Stacy.lauritsen@oregon.gov,orjdcc@firenet.gov,michale.j.cearns@odf.oregon.gov