323 
FNUS76 KPDT 030233
FWSPDT

Spot Forecast for Marks Creek...USFS
National Weather Service Pendleton OR
733 PM PDT Tue Sep 2 2025

Forecast is based on forecast start time of 1900 PDT on September 02. 
***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...Hot and dry conditions will continue through Thursday. 
Winds will be primarily diurnally and terrain driven. RH recovery 
expected to be moderate. Shower and thunderstorm chances are low (<15%). 

.WEDNESDAY...

Sky/weather.........Cloudy (85-95 percent) then becoming mostly 
                    sunny (45-55 percent). 
CWR.................0 percent. 
Chance of lightning.13 percent. 
Max temperature.....85-88. 
Min humidity........15-19 percent. 
Wind (20 ft)........South-southwest winds 4 to 7 mph with gusts up 
                    to 15 mph shifting to the north-northeast late afternoon. 
Ridgetop wind.......South-southwest winds 5 to 9 mph with gusts up 
                    to 15 mph shifting to the north-northeast late afternoon. 
Mixing height.......9300 ft AGL. 
Transport winds.....South-southeast winds 7 to 9 mph early morning, 
                    then becoming north-northeast late afternoon. 
Ventilation Index...Poor (40) increasing to good (640) in the 
                    afternoon. 

.WEDNESDAY NIGHT...

Sky/weather.........Partly cloudy (35-45 percent) then becoming 
                    mostly cloudy (50-60 percent) to partly cloudy 
                    (35-45 percent). 
CWR.................0 percent. 
Chance of lightning.13 percent. 
Min temperature.....62-65. 
Max humidity........40-45 percent. 
Wind (20 ft)........Downslope then down valley winds 2-6 mph. 
Ridgetop wind.......Northeast winds 3-6 mph. 
Mixing height.......800 ft AGL in the evening then 500 ft AGL early 
                    Thursday morning. 
Transport winds.....North-northeast winds 3 to 6 mph early evening, 
                    then shifting to the northeast overnight. 
Ventilation Index...Poor (110) decreasing to poor (30) overnight. 

.THURSDAY...

Sky/weather.........Mostly sunny (25-35 percent). 
CWR.................0 percent. 
Chance of lightning.5 percent. 
Max temperature.....86-89. 
Min humidity........15-20 percent. 
Wind (20 ft)........Terrain-driven winds 2 to 5 mph shifting to the northeast
                    5 to 10 mph with gusts up to 15 mph late afternoon. 
Ridgetop wind.......Terrain-driven winds 2 to 5 mph shifting to the northeast
                    5 to 10 mph with gusts up to 15 mph late afternoon. 
Mixing height.......6200 ft AGL increasing to 11700 ft AGL late in 
                    the afternoon. 
Transport winds.....Northeast around 5 mph shifting to the south 5 
                    to 6 mph early in the morning, then shifting to 
                    the northwest around 8 mph late in the 
                    afternoon. 
Ventilation Index...Poor (30) increasing to fair (400) in the 
                    afternoon. 

$$
Forecaster...Feaster/Plunkett
Requested by...COIMT
Type of request...WILDFIRE
.TAG 2521166.0/PDT
.DELDT 09/02/25
.FormatterVersion 2.0.0
.EMAIL amy.e.lowe@usda.gov