087
FNUS76 KPDT 072027
FWSPDT

Spot Forecast for Rock Crk RX...USFS
National Weather Service Pendleton OR
127 PM PDT Tue Oct 7 2025

Forecast is based on ignition time of 0800 PDT on October 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...A dry cold front will slowly pass over the fire
area Wednesday morning and stall to the east. Good (60-70%)
overnight humidities Wednesday morning, as an inversion breaks
between 0900 and 1000. An offshore system will inject moisture
over the area to promote shower chances late in the afternoon,
intensifying overnight and through Thursday. Expected rain amounts
Wednesday total around 0.06", with an additional 0.17" on
Thursday. The majority of rainfall is expected to occur overnight
and late Thursday afternoon/evening. Temperatures cool and
humidities improve through the period.

.WEDNESDAY...

Sky/weather.........Mostly sunny (30-40 percent). Slight chance
                    (15-20 percent) of rain showers after 1700.
CWR.................0 percent.
Chance of lightning.0 percent.
Max temperature.....Around 70.
Min humidity........31-37 percent.
Wind (20 ft)........West southwest winds 3 to 7 mph becoming west
                    5 to 10 mph with gusts up to 18 mph after
                    1000, peaking between 1400 and 1700.
Ridgetop wind.......West winds 4 to 8 mph increasing to 6 to 12
                    mph with gusts up to 20 mph after 1000,
                    peaking between 1400 and 1700.
Mixing height.......4100 ft AGL.
Transport winds.....West 12 to 16 mph.
Ventilation Index...Poor (130) increasing to good (530) in the
                    afternoon.

TIME (PDT)      8 AM   10 AM  NOON   2 PM   4 PM   6 PM
Chc of ltng (%).0      0      0      0      0      0
Temp............47     57     63     66     63     58
RH..............66     50     43     38     39     45
20 ft wind......SW 5   W 5    W 6    W 8    W 10   W 7
20 ft wind gust.6      6      10     15     17     14

.WEDNESDAY NIGHT...

Sky/weather.........Mostly cloudy (55-65 percent). Slight chance
                    15-25 percent) of rain showers in the evening,
                    then chance (45-50 percent) of rain showers
                    after 2300.
CWR.................0 percent increasing to 25 percent late in the
                    evening.
Chance of lightning.4 percent.
Min temperature.....41-45.
Max humidity........80-84 percent.
Wind (20 ft)........West winds 5 to 10 mph with gusts up to 18 mph,
                    becoming 2 to 6 mph after 1900.
Ridgetop wind.......West winds 6 to 12 mph with gusts up to 20 mph,
                    becoming 3 to 7 mph after 1900.
Mixing height.......800 ft AGL.
Transport winds.....West 5 to 12 mph.
Ventilation Index...Poor (130) decreasing to poor (40) overnight.

.THURSDAY...

Sky/weather.........Mostly cloudy (65-75 percent). Chance (35-45
                    percent) of rain showers, then rain showers
                    likely (50-60 percent) after 1700.
CWR.................17 percent decreasing to 0 percent late in the
                    morning, then increasing to 25 percent late in
                    the afternoon.
Chance of lightning.6 percent.
Max temperature.....60-63.
Min humidity........44-49 percent.
Wind (20 ft)........Light east winds 1 to 4 mph becoming northeast
                    2 to 5 mph after 1300.
Ridgetop wind.......Light east winds 2 to 5 mph becoming northeast
                    3 to 6 mph after 1300.
Mixing height.......2500 ft AGL.
Transport winds.....West around 5 mph shifting to the east 5 to 6
                    mph early in the morning, then shifting to the
                    southeast 6 to 9 mph late in the afternoon.
Ventilation Index...Poor (30) increasing to poor (110) in the
                    afternoon.

$$
Forecaster...Callihan
Requested by...Andrew Bellairs
Type of request...PRESCRIBED
.TAG 2523106.0/PDT
.DELDT 10/07/25
.FormatterVersion 2.0.0
.EMAIL Andrew.s.bellairs@usda.gov