508 FNUS76 KOTX 220422 FWSOTX Spot Forecast for Jameson Lake...BLM National Weather Service Spokane WA 922 PM PDT Fri Aug 21 2026 Forecast is based on forecast start time of 2100 PDT on August 21. ...HEAT ADVISORY IN EFFECT UNTIL 10 PM PDT THIS EVENING... ...RED FLAG WARNING IN EFFECT FROM NOON TO 10 PM PDT SATURDAY... .DISCUSSION... Mid and high clouds continue stream into the area. There is a small risk (20% chance) to receive sprinkles overnight into early Saturday morning. Any activity will be capable of brief erratic wind gusts around 15 mph. Otherwise, winds will be quite dynamic and shifting directions over the next 12-18 hours, generally from the north tonight to northeast Saturday morning, east around midday and south in the afternoon. Speeds will increase significantly after 1200 and become strong in the afternoon and early evening shifting to the southwest then west as a cold front presses through 1600-1900. 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). *************************************************************** .REST OF TONIGHT... Sky/weather.........Cloudy. Haze and patchy smoke. 30% chance of showers. CWR.................0 percent. Chance of lightning.5 percent. Min temperature.....72. Max humidity........33-38 percent. Wind (20 ft)........Northwest winds 5 to 7 mph gusts 11 mph becoming north to northeast around 8 mph after midnight. Erratic winds to 15 mph near showers. Mixing height.......500 ft AGL. Transport winds.....Northeast around 5 mph shifting to the north around 9 mph overnight. Ventilation Index...Low (48). .SATURDAY... Sky/weather.........Mostly sunny. Haze and patchy smoke in the morning. CWR.................0 percent. Chance of lightning.5 percent. Max temperature.....94. Min humidity........13-18 percent. Wind (20 ft)........Northeast to east winds 6 to 10 mph shifting to the south 17 to 25 mph with gusts to around 34 mph in the afternoon after 1400. Winds shifting to the southwest after 1600. Mixing height.......9000 ft AGL in the afternoon. Transport winds.....Southeast 12 to 18 mph becoming south 20 mph. Ventilation Index...High (578) increasing to very high (1568) in the afternoon. .SATURDAY NIGHT... Sky/weather.........Partly cloudy. CWR.................0 percent. Chance of lightning.0 percent. Min temperature.....Around 60. Max humidity........59-64 percent. Wind (20 ft)........West winds 15 to 20 mph. Gusts up to 32 mph in the evening decreasing west 8 to 13 mph overnight. Mixing height.......6500 ft AGL falling to 500 ft AGL. Transport winds.....West 15 to 20 mph. Ventilation Index...Very high (1173) decreasing to low (50) overnight. $$ Forecaster...SB Requested by...Jeremy Holt Type of request...WILDFIRE .TAG 2620225.0/OTX .DELDT 08/21/26 .FormatterVersion 2.0.0 .EMAIL wacwc@firenet.gov,jjkistner@blm.gov  433 FNUS75 KSLC 220450 FWSSLC Spot Forecast for Harley...Northern Utah IFC National Weather Service Salt Lake City UT 1050 PM MDT Fri Aug 21 2026 Forecast is based on forecast start time of 2300 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: showers and thunderstorms over the Utah Valley as of this writing will continue northward, most likely reaching the fire in 2 to 3 hours. These showers will be relatively weak, but will bring a 30-40 percent chance of gusty and erratic winds over the fire and a 10 percent chance of lightning. Showers will diminish as sunrise approaches. For tomorrow and beyond, monsoon moisture will remain in place Saturday, bringing the development of showers and thunderstorms in the afternoon, primarily focused over the higher terrain. However, there will be a 20 percent chance during the day that a storm will impact the fire. During the evening and into the early part of the overnight hours, a weak cold front will move into northwest Utah as it weakens. This will bring a chance (30-40 percent) of showers that could bring some erratic winds gusts. The airmass over the area will dry somewhat Sunday into Monday, but at least some potential for showers and thunderstorms will exist each day. .REST OF TONIGHT... Sky/weather.........Mostly cloudy (80-90 percent cloud cover). CWR.................15 percent. Chance of pcpn......40 percent. Chance of lightning.10 percent. Min temperature.....68-72. Max humidity........60-62 percent. Wind (20 ft)........Downslope/downvalley winds 3-7 mph. Gusty and erratic winds expected near thunderstorms overnight. Mixing height.......500 ft AGL. Transport winds.....South winds 8-12 mph. .SATURDAY... Sky/weather.........Partly cloudy (40-50 percent cloud cover). CWR.................5 percent. Chance of pcpn......20 percent. Chance of lightning.5 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. Mixing height.......10100 ft AGL (60-70th Percentile). Transport winds.....Southwest winds 10-15 mph. Gusty and erratic winds expected near thunderstorms in the afternoon. .SATURDAY NIGHT... Sky/weather.........Partly cloudy (45-55 percent cloud cover). Slight chance of showers and thunderstorms overnight. CWR.................10 percent. Chance of pcpn......30 percent. Chance of lightning.15 percent. Min temperature.....66-70. Max humidity........62-66 percent. Wind (20 ft)........Southwest winds 5-10 mph becoming downslope/downvalley 3-7 mph overnight. Gusty and erratic winds expected near thunderstorms overnight. 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 south 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 2620227.0/SLC .DELDT 08/21/26 .FormatterVersion 2.0.0 .EMAIL trhobbs@utah.gov,utnuc@firenet.gov