166
FNUS76 KPDT 081542
FWSPDT

Spot Forecast for Sunnyside Prescribed Burn...Mt Adams Resource Stewards
National Weather Service Pendleton OR
842 AM PDT Wed Oct 8 2025

Forecast is based on ignition time of 1100 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...Dry conditions are expected to day, but rain chances
will increase tonight through the weekend as an upper low approaches
the Pacific Northwest. MIN RH values will be around 40 percent today
and trend upward over the next few days, with excellent overnight
recoveries.

.TODAY...

Sky/weather.........Sunny (15-25 percent) then becoming partly
                    sunny (45-55 percent).
CWR.................0 percent.
Chance of lightning.0 percent.
Max temperature.....Around 70.
Min humidity........38-43 percent.
Wind (20 ft)........West winds 5 to 8 mph.
Ridgetop wind.......West wind around 10 mph.
Mixing height.......4600 ft AGL.
Transport winds.....West 10 to 15 mph.
Ventilation Index...Good (520).

TIME (PDT)      11 AM  1 PM   3 PM   5 PM   7 PM   9 PM
Chc of ltng (%).0      0      0      0      0      0
Temp............57     64     65     64     58     50
RH..............64     49     44     46     60     74
20 ft wind......W 7    W 7    W 7    W 6    W 6    NW 4
20 ft wind gust.11     11     11     11     11     7

.TONIGHT...

Sky/weather.........Mostly cloudy (70-80 percent). Chance of rain
                    showers (40%) in the evening, then rain showers
                    likely (60%) overnight.
CWR.................0 percent increasing to 45 percent.
Chance of lightning.2 percent.
Min temperature.....39-42.
Max humidity........95-100 percent.
Wind (20 ft)........West winds 5 to 7 mph early in the evening
                    becoming light.
Ridgetop wind.......West wind around 10 mph becoming southeast to south
                    by morning.
Mixing height.......1300 ft AGL.
Transport winds.....West 5 to 10 mph in the evening becoming light,
                    then becoming northwest 5 to 6 mph overnight.
Ventilation Index...Poor (130) decreasing to poor (50) overnight.

.THURSDAY...

Sky/weather.........Cloudy (85-95 percent) then becoming partly
                    sunny (60-70 percent). Chance (40%) of rain showers.
CWR.................45 percent decreasing to 7 percent late in the
                    morning.
Chance of lightning.2 percent.
Max temperature.....Around 70.
Min humidity........47-52 percent.
Wind (20 ft)........Light winds.
Ridgetop wind.......South winds around 10 mph shifting to the west early and
                    increasing to 10 to 15 mph , then decreasing and
                    becoming light and variable by afternoon and becoming
                    east at 10 to 20 mph during the evening.
Mixing height.......3600 ft AGL.
Transport winds.....West around 5 mph early in the morning becoming
                    light, then becoming west around 5 mph late in
                    the morning shifting to the southeast 6 to 9
                    mph.
Ventilation Index...Poor (50) increasing to poor (80) in the
                    afternoon.

.FORECAST DAYS 3 THROUGH 7...
.FRIDAY...
Mostly cloudy. Showers likely. Lows in the upper 30s. Highs in
the mid 60s. Light winds. MIN RH in the 40s to lower 50s percent.
MAX RH 95 to 100 percent.
.SATURDAY...
Showers. Lows in the mid 30s. Highs in the mid 50s. West winds
around 5 mph. MIN RH in the 60s percent.  MAX RH 95 to 100 percent.
.SUNDAY...
Showers. Lows in the lower 30s. Highs in the lower 50s. West
winds around 5 mph. MIN RH in the 60s to around 70 percent. MAX RH
95 to 100 percent.
.COLUMBUS DAY...
Showers likely. Lows in the lower 30s. Highs in the mid 50s. MIN
RH in the upper 50s to around 60 percent. MAX RH 95 to 100 percent.
.TUESDAY...
Partly cloudy. Chance of showers. Lows in the lower 30s. Highs in
the upper 50s. MIN RH in the lower to mid 50s percent.  MAX RH 95
to 100 percent.

$$
Forecaster...Nierenberg
Requested by...Kylie England
Type of request...PRESCRIBED
.TAG 2523121.1/PDT
.DELDT 10/08/25
.FormatterVersion 2.0.0
.EMAIL kylie@mtadamsstewards.org,anthony.dobson@dnr.wa.gov