FNUS76 KOTX 221257
FWSOTX

Spot Forecast for Ptarmigan...USFS
National Weather Service Spokane WA
557 AM PDT Sat Aug 22 2026

Forecast is based on forecast start time of 0600 PDT on August 22. 

...RED FLAG WARNING IN EFFECT FROM 11 AM THIS MORNING TO 8 AM PDT
SUNDAY...

.DISCUSSION...

Winds will increase out of the south today ahead of a cold front
passage, shifting to west 1700 to 1900 with front passage.  Increased 
instability will lead to showers developing, with a 40 percent
chance of thunderstorms. Rain amounts between 0.10 and 0.20 is 
forecast for the fire. Wind gusts up to 25 mph is expected with the 
cold front, but brief stronger gusts up to 40 mph is possible near 
thunderstorms.

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.........Partly sunny. 30 percent chance of showers in 
                    the morning increasing to 70 percent after 1400. 
                    15 percent chance of thunderstorms in the morning 
                    morning increasing to a 40 percent in the 
                    afternoon.
CWR.................60 percent. 
Chance of lightning.10 percent in the early morning increasing to 40 
                    percent after 1200. 
Max temperature.....62-73. 
Min humidity........35-45 percent. 
Wind (20 ft)........Variable 1-4 mph in the morning becoming 
                    south-southwest 8-11 mph with ridgetop winds 
                    15-20 mph near 1200. Gusty and erratic winds 
                    expected near thunderstorms in the afternoon.
Mixing height.......Inversion lifting around 0900. Mixing height 
                    increasing to 4000 ft AGL in the afternoon. 
Transport winds.....Southeast 5-10 mph in the morning shifting to 
                    the southwest 15-20 mph in the afternoon.
Ventilation Index...High (775). 

.TONIGHT...

Sky/weather.........Mostly cloudy. A 70 percent chance of rain showers
                    and 40 percent chance of thunderstorms in the evening
                    then a 20 percent chance of rain showers 
                    overnight. 
CWR.................45 percent. 
Chance of lightning.40 percent. 
Min temperature.....42-47. 
Max humidity........91-100 percent. 
Wind (20 ft)........West winds 5 to 11 mph. Gusty and erratic winds 
                    expected near thunderstorms in the evening. 
Mixing height.......500 ft AGL. 
Transport winds.....West around 10 mph. 
Ventilation Index...Low (132). 

.SUNDAY...

Sky/weather.........Mostly cloudy. A 30 percent chance of rain showers. 
CWR.................5 percent. 
Chance of lightning.10 percent. 
Max temperature.....50-60. 
Min humidity........60-70 percent. 
Wind (20 ft)........West winds 5 to 10 mph. 
Mixing height.......Near surface through 0800 increasing to 3000 ft AGL 
                    in the afternoon. 
Transport winds.....West around 10 mph. 
Ventilation Index...Moderate (384). 

$$
Forecaster...JW
Requested by...Brian Campbell
Type of request...WILDFIRE
.TAG 2620029.2/OTX
.DELDT 08/22/26
.FormatterVersion 2.0.0
.EMAIL brian.d.campbell@usda.gov,William.Burks4@usda.gov,michael.barajas@usda.gov