468
FNUS76 KPDT 222142
FWSPDT

Spot Forecast for Flat...USFS
National Weather Service Pendleton OR
242 PM PDT Fri Aug 22 2025

Forecast is based on forecast start time of 1800 PDT on August 22.
***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 FROM NOON SATURDAY TO 9 PM PDT
WEDNESDAY...

.DISCUSSION...A heat wave will settle in over the region this
weekend, making for hot and dry conditions with poor RH
recoveries. Surface winds will generally flow north to northeast
during the day, flowing lightly out of the south during the early
morning hours. Smoke dispersion will generally be to the south.

.TONIGHT...

Sky/weather.........Mostly clear (10-20 percent) then becoming
                    mostly cloudy (55-65 percent).
CWR.................0 percent.
Chance of lightning.0 percent.
Min temperature.....59-62.
Max humidity........29-34 percent.
Wind (20 ft)........North-Northeast winds 6 to 13 mph with gusts to
                    around 18 mph, becoming South at around 5 mph
                    overnight.
Ridgetop wind.......Northeast 10 to 20 mph.
Mixing height.......500 ft AGL.
Transport winds.....North-Northeast around 12 mph, becoming South at
                    around 5 mph by the early morning.
Ventilation Index...Fair (310) decreasing to poor (50) overnight.

.SATURDAY...

Sky/weather.........Mostly sunny (40-50 percent).
CWR.................0 percent.
Chance of lightning.0 percent.
Max temperature.....93-96.
Min humidity........11-16 percent.
Wind (20 ft)........South-Southwest winds around 5 mph early in the
                    morning, becoming North at 6 to 12 mph by the
                    late morning.
Ridgetop wind.......Northeast 7 to 14 mph.
Mixing height.......4800 ft AGL.
Transport winds.....South around 5 mph early, becoming Northeast
                    around 8 mph by the afternoon.
Ventilation Index...Poor (30) increasing to fair (250) in the
                    afternoon.

.SATURDAY NIGHT...

Sky/weather.........Mostly cloudy (65-75 percent) then becoming
                    partly cloudy (25-35 percent).
CWR.................0 percent.
Chance of lightning.1 percent.
Min temperature.....63-66.
Max humidity........35-40 percent.
Wind (20 ft)........North winds 5 to 10 mph, becoming South at
                    around 5 mph overnight.
Ridgetop wind.......Northeast 6 to 12 mph.
Mixing height.......600 ft AGL.
Transport winds.....North around 8 mph, becoming South-Southwest
                    around 5 mph overnight.
Ventilation Index...Fair (210) decreasing to poor (30) overnight.

.SUNDAY...

Sky/weather.........Mostly sunny (30-40 percent).
CWR.................0 percent.
Chance of lightning.3 percent.
Max temperature.....95-98.
Min humidity........13-18 percent.
Wind (20 ft)........Southwest winds around 5 mph early, shifting to
                    the Northeast 5 to 10 mph by the early afternoon.
Ridgetop wind.......Northeast 7 to 14 mph.
Mixing height.......7000 ft AGL.
Transport winds.....Southwest around 5 mph early, becoming
                    North-Northeast around 8 mph by the
                    afternoon.
Ventilation Index...Poor (30) increasing to fair (290) in the
                    afternoon.

$$
Forecaster...Evans
Requested by...COIMT
Type of request...WILDFIRE
.TAG 2520474.0/PDT
.DELDT 08/22/25
.FormatterVersion 2.0.0
.EMAIL amy.e.lowe@usda.gov