548
FNUS76 KPDT 151039
FWSPDT

Spot Forecast for VANSYCLE/BUTLER GRADE FIRE...WALLA WALLA COUNTY FIRE DISTRICT 4
National Weather Service Pendleton OR
339 AM PDT Tue Jul 15 2025

Forecast is based on forecast start time of 0400 PDT on July 15.
***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...Breezy north to northwest winds easing tonight. RHs
in the low 30s this afternoon dipping into the lower 20s
Wednesday afternoon. Overnight recoveries will be moderate to
good. Inversions will develop near surface after midnight, and are
expected to begin breaking after 11AM.

.REST OF TONIGHT...

Sky/weather.........Mostly clear (5-15 percent). Haze.
CWR.................0 percent.
Chance of lightning.0 percent.
Min temperature.....61-64.
Max humidity........56-61 percent.
Wind (20 ft)........Northwest winds 7 to 13 mph.
Ridgetop wind.......Northwest 9 to 15 mph.
Mixing height.......500 ft AGL early in the morning.
Transport winds.....Northwest around 13 mph.
Ventilation Index...Poor (30).

TIME (PDT)      4 AM   6 AM   8 AM   10 AM  NOON   2 PM
Chc of ltng (%).0      0      0      0      0      0
Temp............63     61     66     71     76     81
RH..............58     61     56     53     47     42
20 ft wind......NW 12  NW 13  NW 14  NW 14  N 14   N 15
20 ft wind gust.14     14     16     16     18     19

.TODAY...

Sky/weather.........Sunny (0-10 percent). Haze.
CWR.................0 percent.
Chance of lightning.0 percent.
Max temperature.....83-86.
Min humidity........32-37 percent.
Wind (20 ft)........Northwest winds 8 to 14 mph shifting to the
                    north 9 to 15 mph late in the morning.
Ridgetop wind.......Northwest winds 9 to 15 mph shifting to the
north 12 to 18 mph after 11AM.
Mixing height.......7500 ft AGL.
Transport winds.....North 13 to 18 mph.
Ventilation Index...Poor (190) increasing to excellent (790) in the
                    afternoon.

.TONIGHT...

Sky/weather.........Mostly clear (5-15 percent).
CWR.................0 percent.
Chance of lightning.0 percent.
Min temperature.....Around 60.
Max humidity........63-68 percent.
Wind (20 ft)........North winds 5 to 15 mph shifting to the
                    northwest 5 to 7 mph early in the morning.
Ridgetop wind.......North winds 12 to 18 mph decreasing to 7 to
12 mph after 12AM, then shifting to the west
5 to 10 mph around 5AM.
Mixing height.......6900 ft AGL early in the evening.
Transport winds.....North 9 to 18 mph shifting to the northwest
                    around 6 mph overnight.
Ventilation Index...Good (560) decreasing to poor (30) overnight.

.WEDNESDAY...

Sky/weather.........Sunny (0-10 percent).
CWR.................0 percent.
Chance of lightning.0 percent.
Max temperature.....Around 90.
Min humidity........19-24 percent.
Wind (20 ft)........Northwest winds 5 to 8 mph shifting to the west
                    early in the morning, then shifting to the
                    northwest late in the morning.
Ridgetop wind.......West winds 5 to 10 mph shifting to the northwest
around 11AM.
Mixing height.......4900 ft AGL early in the morning.
Transport winds.....Northwest 6 to 8 mph.
Ventilation Index...Poor (40) increasing to fair (260) in the
                    afternoon.

$$
Forecaster...NWS Seattle
Requested by...BRANDON MCKINNEY
Type of request...WILDFIRE
.TAG 2518023.2/PDT
.DELDT 07/15/25
.FormatterVersion 2.0.0
.EMAIL bmckinney@wwfire4.com,imt@wwfire4.com