FNUS76 KOTX 231927
FWSOTX

Spot Forecast for Upper Smith South...Upper Smith
National Weather Service Spokane WA
1227 PM PDT Sun Aug 23 2026

Forecast is based on forecast start time of 1300 PDT on August 24. 
.DISCUSSION...

209: A cold front passed through the friday early Sunday morning bringing 
showers, thunderstorms, and gusty winds. Rainfall varied from a few hundreths 
to just over a tenth of an inch.  Sunday was cooler with higher humidity.  
Winds were breezy from the southwest with gusts near 20 mph.  Another 
round of showers and thunderstorms impacted the fire Sunday afternoon.

High pressure will begin to build over the region Monday and 
Tuesday.  This will deliver a warming and drying trend with light 
terrain driven winds.  The heat will continue into Wednesday with 
a subtle increase in moisture.  This will allow for increasing 
afternoon instability and 10-20% chance for afternoon thunderstorms.  

Spot discussion: Good to excellent recoveries this morning will give 
way to a subtle warming and drying trend Monday afternoon.  Winds 
will be light and terrain driven.  A stronger warming and drying 
trend develops Tuesday into Wednesday pushing afternoon temperatures 
in the 90s in the valley and mid 80s on the ridgetops.  Winds will
remain light and largely terrain driven.  Afternoon conditions will 
become increasingly unstable with a 10-20% chance for thunderstorms 
by Wednesday afternoon.  The next cold front is forecast to arrive 
Wednesday night into Thursday.   

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

.MONDAY...

Sky/weather.........Sunny becoming partly cloudy. 
CWR.................0 percent. 
Chance of lightning.0 percent. 
Max temperature.....72 ridgetop to 84 valley bottom. 
Min humidity........37-42 percent. 
Wind (20 ft)........Variable winds 0 to 3 mph becoming 
                    upslope/upvalley 1 to 4 mph. 
Mixing height.......5000 ft AGL. 
Transport winds.....Variable to east 1 to 3 mph. 
Ventilation Index...Moderate (214). 

.MONDAY NIGHT...

Sky/weather.........Partly cloudy then mostly clear. 
                    Haze and areas of smoke. 
CWR.................0 percent. 
Chance of lightning.0 percent. 
Min temperature.....46-51. 
Max humidity........65-85 percent. 
Wind (20 ft)........Variable winds 0 to 3 mph. 
Mixing height.......3000 ft AGL falling to near surface. 
Transport winds.....Northeast 3 mph. 
Ventilation Index...Low (120). 

.TUESDAY...

Sky/weather.........Sunny. 
CWR.................0 percent. 
Chance of lightning.0 percent. 
Max temperature.....83 ridgetop to 93 valley bottom.  
Min humidity........25-30 percent. 
Wind (20 ft)........Upslope/upvalley 3 to 8 mph. 
Mixing height.......6500 ft AGL in the afternoon. 
Transport winds.....Northeast around 6 mph shifting to the south 
                    around 8 mph in the afternoon. 
Ventilation Index...Moderate (218) increasing to moderate (445) in 
                    the afternoon. 

$$
Forecaster...SB
Requested by...Noelle
Type of request...WILDFIRE
.TAG 2620106.3/OTX
.DELDT 08/23/26
.FormatterVersion 2.0.0
.EMAIL idcdc@firenet.gov,david_pearson@firenet.gov,2026.uppersmith.plans@firenet.gov