FNUS76 KOTX 220224
FWSOTX

Spot Forecast for Porcupine...USFS
National Weather Service Spokane WA
724 PM PDT Fri Aug 21 2026

Forecast is based on forecast start time of 1900 PDT on August 21. 
...HEAT ADVISORY IN EFFECT UNTIL 10 PM PDT THIS EVENING...
...RED FLAG WARNING IN EFFECT FROM 4 PM SATURDAY TO 11 AM PDT
SUNDAY...

.DISCUSSION...

Mid and high clouds continue to be thicken. This activity has a 
20% chance to produce sprinkles overnight into early Saturday 
morning. Any activity will be capable of brief erratic wind gusts 
of 15-20 mph. The threat for showers will move out by 0700 with a 
15% chance for thunderstorms in the afternoon mainly between 
1700-2000, with chances increasing to 30% until 0800 Sunday. Any 
storms will be capable of gusty outflow winds around 30-50 mph and
brief rain with low probabilities for wetting rains. Winds 
overall will be light besides thunderstorm outflows. Sunday will 
be cooler in the upper 60s. 

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). 
***************************************************************

.TONIGHT...

Sky/weather.........Mostly cloudy. 10 percent chance of sprinkles 
                    from 0000-0700. 
CWR.................0 percent. 
Chance of lightning.5 percent. 
Min temperature.....70. 
Max humidity........40-45 percent. 
Wind (20 ft)........Downslope/downvalley winds 1-3 mph. Gusty and 
                    erratic winds up to 20 mph around sprinkles. 
Mixing height.......Near surface.  
Transport winds.....Northeast 7 to 8 mph. 
Ventilation Index...Low (40). 

.SATURDAY...

Sky/weather.........Mostly cloudy becoming partly cloudy in the early 
                    afternoon. 15 percent chance of thunderstorms 
                    from 1700-2000 hours. Thunderstorms will carry 
                    little rain.
CWR.................5 percent. 
Chance of lightning.15 percent. 
Max temperature.....85. 
Min humidity........28-33 percent. 
Wind (20 ft)........Light and variable winds 1-3 mph. Gusty and erratic
                    outflow winds around 30-50 mph around thunderstorms.    
Mixing height.......4000 ft AGL.
Transport winds.....East around 8 mph shifting to the south around 
                    9 mph in the afternoon. 
Ventilation Index...Moderate (312) increasing to high (529) in the 
                    afternoon. 

.SATURDAY NIGHT...

Sky/weather.........Mostly cloudy. 30 percent chance of thunderstorms 
                    overnight. Thunderstorms will contain very brief 
                    heavy rain. Training thunderstorms will lead 
                    to a wetting rain. 
CWR.................15 percent. 
Chance of lightning.30 percent. 
Min temperature.....58. 
Max humidity........75-85 percent. 
Wind (20 ft)........Southwest winds 3 to 6 mph in the evening 
                    becoming light. Gusty and erratic outflow winds 
                    around 30-50 mph around thunderstorms.     
Mixing height.......Falling to near surface around 1930. 
Transport winds.....Southwest around 7 mph. 
Ventilation Index...Low (189). 

$$
Forecaster...DB
Requested by...IDCDC
Type of request...WILDFIRE
.TAG 2620220.0/OTX
.DELDT 08/21/26
.FormatterVersion 2.0.0
.EMAIL IDCDC@firenet.gov