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