432  
FNUS75 KSLC 220025  
FWSSLC  
 
SPOT FORECAST FOR HARLEY...NORTHERN UTAH IFC  
NATIONAL WEATHER SERVICE SALT LAKE CITY UT  
625 PM MDT FRI AUG 21 2026  
 
FORECAST IS BASED ON FORECAST START TIME OF 1900 MDT ON AUGUST 21.  
IF CONDITIONS BECOME UNREPRESENTATIVE...CONTACT THE NATIONAL WEATHER  
SERVICE.  
   
..HEAT ADVISORY IN EFFECT UNTIL 7 AM MDT SATURDAY  
 
   
DISCUSSION  
FOR THE NEXT FEW HOURS: AN AREA OF WEAKENING SHOWERS  
AND THUNDERSTORMS WILL MOVE OVER THE FIRE IN THE NEXT 30 TO 45  
MINUTES. RAIN WILL BE ON THE LIGHT SIDE BUT THERE IS A GOOD  
CHANCE OF SOME WIND GUSTS IN EXCESS OF 30 MPH AND A LOW (20  
PERCENT) CHANCE OF LIGHTNING. NOT CURRENTLY SEEING ANY SHOWERS  
BEHIND THESE BUT THERE IS A CHANCE (30 TO 40 PERCENT) OF  
ADDITIONAL SHOWERS DEVELOPING DURING THE LATE EVENING INTO THE  
EARLY PART OF THE OVERNIGHT HOURS. BIG PICTURE: HIGH PRESSURE OVER  
THE FOUR CORNERS WILL KEEP MONSOON MOISTURE OVER THE AREA THROUGH  
EARLY NEXT WEEK. THIS WILL BRING DOWN TEMPERATURES AND BRING UP RH  
VALUES, BUT THERE WILL BE A DAILY THREAT (20-30 PERCENT CHANCE)  
EACH DAY OF SHOWERS AND THUNDERSTORMS FOR THE FIRE, PRIMARILY  
DURING THE AFTERNOON AND EARLY EVENING. AWAY FROM THUNDERSTORMS,  
WINDS WILL BE GENERALLY LIGHT AND TERRAIN DRIVEN.  
   
REST OF TONIGHT  
 
SKY/WEATHER.........MOSTLY CLOUDY (70-80 PERCENT CLOUD COVER). SLIGHT  
CHANCE OF SHOWERS AND THUNDERSTORMS.  
CWR.................5 PERCENT.  
CHANCE OF PCPN......20 PERCENT.  
CHANCE OF LIGHTNING.10 PERCENT.  
MIN TEMPERATURE.....70-74.  
MAX HUMIDITY........58-62 PERCENT.  
WIND (20 FT)........DOWNSLOPE/UPVALLEY WINDS 3-7 MPH. GUSTY AND ERRATIC WINDS  
EXPECTED NEAR THUNDERSTORMS.  
MIXING HEIGHT.......500 FT AGL.  
TRANSPORT WINDS.....SOUTH WINDS 8-12 MPH.  
   
SATURDAY  
 
SKY/WEATHER.........PARTLY CLOUDY (40-50 PERCENT CLOUD COVER). SLIGHT CHANCE  
OF SHOWERS AND THUNDERSTORMS IN THE AFTERNOON.  
CWR.................5 PERCENT.  
CHANCE OF PCPN......20 PERCENT.  
CHANCE OF LIGHTNING.10 PERCENT.  
MAX TEMPERATURE.....92-96.  
MIN HUMIDITY........24-28 PERCENT.  
WIND (20 FT)........UPSLOPE/UPVALLEY WINDS 3-7 MPH BECOMING  
SOUTH 8-12 MPH IN THE AFTERNOON. GUSTY AND ERRATIC WINDS  
EXPECTED NEAR THUNDERSTORMS IN THE AFTERNOON.  
MIXING HEIGHT.......10100 FT AGL (60-70TH PERCENTILE).  
TRANSPORT WINDS.....SOUTHWEST WINDS 10-15 MPH.  
   
SATURDAY NIGHT  
 
SKY/WEATHER.........PARTLY CLOUDY (45-55 PERCENT CLOUD COVER).  
SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS.  
CWR.................5 PERCENT.  
CHANCE OF PCPN......20 PERCENT.  
CHANCE OF LIGHTNING.10 PERCENT.  
MIN TEMPERATURE.....66-70.  
MAX HUMIDITY........64-68 PERCENT.  
WIND (20 FT)........SOUTHWEST WINDS 5-10 MPH BECOMING DOWNSLOPE/DOWNVALLEY  
3-7 MPH IN THE LATE EVENING AND OVERNIGHT. GUSTY  
AND ERRATIC WINDS EXPECTED NEAR THUNDERSTORMS.  
MIXING HEIGHT.......500 FT AGL.  
TRANSPORT WINDS.....SOUTHWEST WINDS 8-12 MPH.  
   
SUNDAY  
 
SKY/WEATHER.........MOSTLY SUNNY (10-20 PERCENT CLOUD COVER).  
CWR.................5 PERCENT.  
CHANCE OF PCPN......20 PERCENT.  
CHANCE OF LIGHTNING.10 PERCENT.  
MAX TEMPERATURE.....92-96.  
MIN HUMIDITY........24-28 PERCENT.  
WIND (20 FT)........UPSLOPE/UPVALLEY WINDS 3-7 MPH BECOMING SOUTHWEST  
8-12 MPH IN THE AFTERNOON. GUSTY AND ERRATIC  
WINDS EXPECTED NEAR THUNDERSTORMS IN THE  
AFTERNOON.  
MIXING HEIGHT.......700 FT AGL INCREASING TO 11600 FT AGL IN THE  
AFTERNOON (70-80TH PERCENTILE).  
TRANSPORT WINDS.....SOUTHWEST WINDS 8-12 MPH.  
 
 
FORECASTER...TRAPHAGAN  
REQUESTED BY...NORTHERN UTAH IFC  
TYPE OF REQUEST...WILDFIRE  
.TAG 2620214.0/SLC  
.DELDT 08/21/26  
.FORMATTERVERSION 2.0.0  
.EMAIL UTNUC@FIRENET.GOV, DUSTINRICHARDS@UTAH.GOV  
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