371
FNUS76 KOTX 261033
FWSOTX

Spot Forecast for Upper Smith Fire...USFS
National Weather Service Spokane WA
333 AM PDT Sat Sep 26 2026

Forecast is based on forecast start time of 0600 PDT on September 26.
.DISCUSSION...

Fall-like conditions over the fire today with shallow afternoon
buildups and slight chance for a light shower or sprinkle.  Southwest
winds will be breezy over the ridgetops in the morning with trends
toward decreasing winds through the day.  Winds become light overnight
with mostly clear skies promoting temperatures near or below freezing.
A warming and drying trend returns on Sunday with light, terrain driven
winds.

If conditions become unrepresentative, contact the National Weather
Service.
***************************************************************
Forecasts for 20 foot wind speeds (valleys and ridge tops) are
10 minute averages reflecting RAWS wind.
***Ventilation Index is derived from transport wind
   multiplied by the mixing height divided by 100.
   Categories: low (< 200), moderate (200-500),
   high (500-800), and very high (> 800).
***************************************************************

.TODAY...

Sky/weather.........Mostly cloudy becoming partly cloudy.  A slight
                    chance for light showers through the afternoon.
CWR.................5 percent.
Chance of lightning.2 percent.
Max temperature.....Ridgetops:39-43.
                    Valleys: 51-54.
Min humidity........Ridgetops: 63-67 percent.
                    Valleys: 48-53 percent.
Wind (20 ft)........Southwest winds 6 to 12 mph. Gusts 15 to 18 mph...
                    decreasing southwest 5 to 9 mph gusts to 15 mph in
                    the afternoon.
Mixing height.......4000 ft AGL in the afternoon.
Transport winds.....West 13 to 15 mph.
Ventilation Index...Moderate (454).

.TONIGHT...

Sky/weather.........Mostly clear then becoming partly cloudy.
CWR.................0 percent.
Chance of lightning.0 percent.
Min temperature.....Ridgetops: 32-36.
                    Valleys: 30-33.
Max humidity........Ridgetops: 70-75 percent.
                    Valleys: 80-85 percent.
Wind (20 ft)........Variable to downslope winds 0 to 3 mph.
Mixing height.......Near surface.
Transport winds.....West around 6 mph shifting to the north around
                    3 mph overnight.
Ventilation Index...Low (136).

.SUNDAY...

Sky/weather.........Partly cloudy becoming mostly sunny.
CWR.................0 percent.
Chance of lightning.0 percent.
Max temperature.....Ridgetops:44-47.
                    Valleys: 56-61.
Min humidity........Ridgetops: 39-44 percent.
                    Valleys: 32-36 percent.
Wind (20 ft)........Upslope/upvalley or east to northeast 2 to 6 mph.
Mixing height.......4400 ft AGL in the afternoon.
Transport winds.....Northeast around 5 mph shifting to the east in
                    the afternoon.
Ventilation Index...Moderate (220).

$$
Forecaster...SB
Requested by...Patrick Reinbold
Type of request...WILDFIRE
.TAG 2622519.0/OTX
.DELDT 09/26/26
.FormatterVersion 2.0.0
.EMAIL patrick.reinbold@usda.gov