586  
FNUS76 KOTX 272110  
FWSOTX  
 
SPOT FORECAST FOR SINLAHEKIN...USFS  
NATIONAL WEATHER SERVICE SPOKANE WA  
210 PM PDT SUN SEP 27 2026  
 
FORECAST IS BASED ON FORECAST START TIME OF 0600 PDT ON SEPTEMBER 28.  
   
DISCUSSION
 
 
A WEATHER SYSTEM WILL APPROACH ON MONDAY WITH INCREASED SOUTHERLY WINDS  
UP THE OKANOGAN VALLEY AND ON RIDGES IN THE AFTERNOON. MOISTURE  
INCREASES MONDAY NIGHT INTO TUESDAY WITH INCREASING CLOUDS AND A CHANCE  
FOR RAIN ON TUESDAY. SOUTHWEST WINDS WILL ALSO BE ON THE INCREASE WITH  
GUSTS UP TO 35 MPH ON TUESDAY WITH STRONGEST WINDS ON UPPER SLOPES  
AND RIDGETOPS.  
 
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.........MOSTLY SUNNY.  
CWR.................0 PERCENT.  
CHANCE OF LIGHTNING.0 PERCENT.  
MAX TEMPERATURE.....VALLEYS (BELOW 3000 FT)...63-67.  
RIDGES (ABOVE 5000 FT)...54-58.  
MIN HUMIDITY........VALLEYS (BELOW 3000 FT)...31-37 PERCENT.  
RIDGES (ABOVE 5000 FT)...41-45 PERCENT.  
WIND (20 FT)........VALLEYS TO MID-SLOPES: DOWNSLOPE/DOWN-VALLEY  
WINDS 2 TO 4 MPH EARLY IN THE MORNING BECOMING  
UPSLOPE/UP-VALLEY 3 TO 6 MPH AFTER 0900.  
UPPER SLOPES TO RIDGES: NORTHWEST WINDS 3 TO  
6 MPH IN THE MORNING BECOMING SOUTHWEST 5 TO 10  
MPH AFTER 1100.  
   
MONDAY NIGHT
 
 
SKY/WEATHER.........MOSTLY CLOUDY.  
CWR.................0 PERCENT.  
CHANCE OF LIGHTNING.0 PERCENT.  
MIN TEMPERATURE.....VALLEYS (BELOW 3000 FT)...43-48.  
RIDGES (ABOVE 5000 FT)...37-42.  
MAX HUMIDITY........75-90 PERCENT.  
WIND (20 FT)........SOUTHWEST 5 TO 13 MPH. GUSTS UP TO 25 MPH  
OVERNIGHT ON UPPER SLOPES AND RIDGETOPS.  
   
TUESDAY
 
 
SKY/WEATHER.........MOSTLY CLOUDY. CHANCE OF RAIN.  
CWR.................15 PERCENT.  
CHANCE OF LIGHTNING.0 PERCENT.  
MAX TEMPERATURE.....VALLEYS (BELOW 3000 FT)...58-62.  
RIDGES (ABOVE 5000 FT)...48-53.  
MIN HUMIDITY........50-65 PERCENT.  
WIND (20 FT)........SOUTHWEST WINDS 8 TO 15 MPH WITH GUSTS UP  
TO 35 MPH. STRONGEST WINDS ON UPPER SLOPES  
AND RIDGETOPS.  
 

 
FORECASTER...JW  
REQUESTED BY...APRIL MILLER  
TYPE OF REQUEST...WILDFIRE  
.TAG 2622514.1/OTX  
.DELDT 09/27/26  
.FORMATTERVERSION 2.0.0  
.EMAIL CHRISTOPHER_MILLER@FIRENET.GOV  
 
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