400 
FNUS76 KPDT 050027
FWSPDT

Spot Forecast for STONE...high dessert team 3
National Weather Service Pendleton OR
527 PM PDT Thu Sep 4 2025

Forecast is based on forecast start time of 2000 PDT on September 04. 
***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.

...HEAT ADVISORY IN EFFECT UNTIL 8 PM PDT THIS EVENING...
...FIRE WEATHER WATCH IN EFFECT FROM FRIDAY AFTERNOON THROUGH
FRIDAY EVENING...

.DISCUSSION...Hot, dry and unstable conditions will persist over the 
fire area through Friday. Chc of lightning will be 15-18% through Friday 
night with highest confidence Saturday 20-25%. Storms Friday will be 
mostly dry with little to no precip while Saturdays are expected to be 
wet. Friday the inversion is expected to break around 1030 and instability 
will follow. Overnight RH recoveries tonight will be moderate with min RHs 
Friday being poor. RHs will recover slightly Friday night into good and 
daytime RHs Saturday will be moderate. Winds will be below 10 mph each 
day with DS/DV nighttime winds. 

.TONIGHT...

Sky/weather.........Partly cloudy (35-45 percent). Slight chance of 
                    showers and thunderstorms in the evening. Haze 
                    early in the evening. Haze early in the 
                    morning. 
CWR.................0 percent. 
Chance of lightning.15 percent. 
Min temperature.....61-64. 
Max humidity........48-53 percent. 
Wind (20 ft)........North winds 5 to 7 mph becoming light around 8 PM.
                    Gusty and erratic winds expected near thunderstorms
                    through 11 PM. 
Ridgetop wind.......North winds 7 to 9 mph becoming downslope/down-valley
                    around 8 PM. Gusty and erratic winds expected near 
                    thunderstorms through 11 PM. 
Mixing height.......500 ft AGL in the evening. 
Transport winds.....North around 5 mph shifting to the northeast 5 
                    to 8 mph early in the evening. 
Ventilation Index...Poor (130) decreasing to poor (30) overnight. 

TIME (PDT)      6 PM   8 PM   10 PM  MIDNGT 2 AM   4 AM   
Chc of ltng (%).20     20     20     0      0      0      
Temp............87     79     73     68     67     64     
RH..............22     31     36     42     44     48     
20 ft wind......N 5    E 4    E 4    S 4    SE 4   SE 4   
20 ft wind gust.8      5      5      5                    

.FRIDAY...

Sky/weather.........Mostly sunny (40-50 percent). Haze. Slight 
                    chance of showers late in the morning. Slight 
                    chance of thunderstorms late in the morning. 
                    Chance of showers late in the afternoon. 
CWR.................5 percent. 
Chance of lightning.18 percent. 
Max temperature.....89-92. 
Min humidity........18-23 percent. 
Wind (20 ft)........Downslope/down-valley becoming east 5 to 7 mph 
                    around 2 PM. Gusty and erratic winds expected 
                    near thunderstorms beginning around 2 PM. 
Ridgetop wind.......Downslope/down-valley becoming east 7 to 9 mph 
                    around 2 PM. Gusty and erratic winds expected 
                    near thunderstorms beginning around 2 PM. 
Mixing height.......7800 ft AGL early in the morning. 
Transport winds.....East 5 to 10 mph. 
Ventilation Index...Poor (30) increasing to fair (330) in the 
                    afternoon. 

.FRIDAY NIGHT...

Sky/weather.........Mostly cloudy (60-70 percent). Chance of 
                    showers and slight chance of thunderstorms in 
                    the evening, then slight chance of showers late 
                    in the evening. 
CWR.................5 percent. 
Chance of lightning.18 percent. 
Min temperature.....60-63. 
Max humidity........65-70 percent. 
Wind (20 ft)........East winds 5 to 7 mph through 8 PM becoming 
                    downslope/down-valley. Gusty and erratic winds 
                    expected near thunderstorms through 11 PM. 
Ridgetop wind.......East winds 7 to 9 mph through 8 PM becoming 
                    downslope/down-valley. Gusty and erratic winds 
                    expected near thunderstorms through 11 PM. 
Mixing height.......500 ft AGL in the evening then 500 ft AGL 
                    overnight. 
Transport winds.....East around 10 mph shifting to the north around 
                    9 mph early in the evening, then shifting to 
                    the west around 12 mph late in the evening 
                    shifting to the southeast 6 to 7 mph overnight. 
Ventilation Index...Poor (100) decreasing to poor (30) overnight. 

.SATURDAY...

Sky/weather.........Partly sunny (60-70 percent). Slight chance of 
                    showers in the morning, then chance of showers 
                    late in the morning. Slight chance of 
                    thunderstorms late in the afternoon. 
CWR.................0 percent increasing to 45 percent late in the 
                    morning, then decreasing to 6 percent late in 
                    the afternoon. 
Chance of lightning.23 percent. 
Max temperature.....82-85. 
Min humidity........32-37 percent. 
Wind (20 ft)........Downslope/down-valley becoming northeast 5 to 7 mph 
                    around 2 PM. Gusty and erratic winds expected near 
                    thunderstorms after 2 PM through 11 PM. 
Ridgetop wind.......Downslope/down-valley becoming northeast 7 to 9 mph 
                    around 2 PM. Gusty and erratic winds expected near 
                    thunderstorms after 2 PM through 11 PM. 
Mixing height.......6200 ft AGL late in the morning. 
Transport winds.....Southeast 5 to 9 mph shifting to the southwest 
                    around 14 mph late in the afternoon. 
Ventilation Index...Poor (30) increasing to fair (240) in the 
                    afternoon. 


$$
Forecaster...Bennese
Requested by...chistoph
Type of request...WILDFIRE
.TAG 2521348.1/PDT
.DELDT 09/04/25
.FormatterVersion 2.0.0
.EMAIL michale.j.cearns@odf.oregon.gov,Stacy.lauritsen@oregon.gov,orjdcc@firenet.gov