FNUS76 KPDT 191903 FWSPDT Spot Forecast for Sun Country...SE WA Type 3 IMT - Team 3 National Weather Service Pendleton OR Issued by National Weather Service Spokane WA 1203 PM PDT Tue Aug 19 2025 Forecast is based on forecast start time of 0700 PDT on August 20. ***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... Dry conditions are expected through Thursday. Breezy west to northwest winds will develop late Wednesday morning through Wednesday afternoon with gusts to 25 mph. Winds will subside late Wednesday night into Thursday. Minimum humidity values will start out in the 30 to 40 percent range on Wednesday and will trend drier, dropping into the 15 to 20 percent range Thursday and Friday. Overnight recoveries will be moderate Wednesday night becoming poor Thursday night. .WEDNESDAY... Sky/weather.........Partly sunny (55-65 percent cloud cover) in the early morning becoming sunny (0-20 percent cloud cover) after 0900 PDT. CWR.................0 percent. Chance of lightning.0 percent. Max temperature.....76. Min humidity........35 percent. Wind (20 ft)........West winds 10 to 15 mph. Gusts up to 25 mph late in the morning through the evening. Ridgetop wind.......Northwest wind 15 to 20 mph. Gusts to 30 mph. Mixing height.......Inversion breaking around 0900 PDT. Rising to 5000 ft AGL in the afternoon. Transport winds.....West 14 to 18 mph. Ventilation Index...Fair (320) increasing to good (620) in the afternoon. TIME (PDT) 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM 6PM Chc of ltng (%).0 0 0 0 0 0 0 0 0 0 0 0 Temp............56 59 63 66 69 71 73 74 75 76 75 73 RH..............80 74 63 55 50 45 41 38 36 35 36 40 20 FT wind dir..W W W WNW WNW WNW WNW WNW WNW WNW WNW WNW 20 FT wind spd..6 7 7 9 10 11 13 14 15 15 14 14 20 FT wind gust.11 12 12 14 16 18 23 24 25 25 24 24 .WEDNESDAY NIGHT... Sky/weather.........Clear (0-10 percent cloud cover). CWR.................0 percent. Chance of lightning.0 percent. Min temperature.....52. Max humidity........63 percent. Wind (20 ft)........West northwest winds 12 to 15 mph in the evening decreasing to 5 to 8 mph overnight. Ridgetop wind.......West northwest 15 to 18 mph in the evening becoming northwest 8 to 11 mph overnight. Mixing height.......Inversion setting in by 2100 PDT. Falling to 700 ft AGL overnight. Transport winds.....West 17 to 21 mph shifting to the northwest around 10 mph early in the morning. Ventilation Index...Fair (460) decreasing to poor (160) overnight. .THURSDAY... Sky/weather.........Sunny (0-10 percent cloud cover). CWR.................0 percent. Chance of lightning.0 percent. Max temperature.....85. Min humidity........19 percent. Wind (20 ft)........Light winds becoming east 5 to 7 mph late in the morning. Ridgetop wind.......Northwest 4 to 6 mph becoming southeast 5 to 7 mph late in the morning. Mixing height.......Increasing to 4500 ft AGL in the afternoon. Transport winds.....Northwest 5 to 7 mph shifting to the southeast late in the morning. Ventilation Index...Poor (90) increasing to fair (290) in the afternoon. $$Forecaster...NWS Spokane Requested by...Ryan Scharnhorst Type of request...WILDFIRE .TAG 2520241.0/PDT .DELDT 08/19/25 .FormatterVersion 2.0.0 .EMAIL ryan_scharnhorst@firenet.gov