FNUS75 KTFX 200141 FWSTFX Spot Forecast for Sawmill...DNRC National Weather Service Great Falls MT 741 PM MDT Tue Aug 19 2025 Forecast is based on forecast start time of 1900 MDT on August 19. If conditions become unrepresentative...contact the National Weather Service. .DISCUSSION... Isolated to scattered thunderstorms are expected through the rest of the evening with the chance for thunder around the fire increasing after 8 PM and continuing through 2 AM. These storms may produce localized heavy downpours but the main concern will be gusty and erratic winds. Outside of thunderstorm activity, winds will remain light and variable through the overnight hours. Temperatures overnight will drop down into the upper 50s with humidities recovering to around 70%. Wednesday will be another hot and dry day with highs near 90 and minimum RH in the upper teens. A cold front is expected to arrive late Wednesday afternoon which will provide a wind shift as well as a chance for thunderstorms into the evening hours. .REST OF TONIGHT... Sky/weather.........Partly cloudy (35-45 percent). Chance of showers and thunderstorms in the evening, then slight chance of showers and thunderstorms overnight. CWR.................5 percent. Chance of thunder...34 percent. Min temperature.....55-60. Max humidity........64-69 percent. Wind (20 ft)........ Slope/valley.......North winds around 5 mph in the evening and overnight becoming light. Gusty and erratic winds expected near thunderstorms early in the evening. Ridgetop...........West around 5 mph increasing to north 15 to 20 mph early in the evening, then shifting to the northeast 10 to 15 mph late in the evening. Mixing height.......500 ft AGL. Transport winds.....West around 10 mph shifting to the north early in the evening. .WEDNESDAY... Sky/weather.........Sunny (15-25 percent). Slight chance of showers and thunderstorms late in the afternoon. CWR.................5 percent. Chance of thunder...15 percent. Max temperature.....89-94. Min humidity........13-18 percent. Wind (20 ft)........ Slope/valley.......Variable winds up to 5 mph. Gusty and erratic winds expected near thunderstorms late in the afternoon. Ridgetop...........East 5 to 10 mph shifting to the south late in the morning, then shifting to the southwest 10 to 15 mph early in the afternoon increasing to west 20 to 25 mph late in the afternoon. Mixing height.......10000 ft AGL increasing to 11500 ft AGL late in the afternoon. Transport winds.....West around 5 mph shifting to the south late in the morning, then increasing to west 15 to 20 mph in the afternoon. .WEDNESDAY NIGHT... Sky/weather.........Partly cloudy (30-40 percent). Slight chance of showers and thunderstorms in the evening. CWR.................5 percent. Chance of thunder...15 percent. Min temperature.....51-56. Max humidity........68-73 percent. Wind (20 ft)........ Slope/valley.......West winds 5 to 10 mph in the evening and overnight becoming light. Gusty and erratic winds expected near thunderstorms in the evening. Ridgetop...........West 20 to 25 mph decreasing to 10 to 15 mph overnight. Mixing height.......500 ft AGL. Transport winds.....West 15 to 20 mph becoming northwest 5 to 10 mph in the late evening and overnight. .THURSDAY... Sky/weather.........Sunny (15-25 percent). CWR.................0 percent. Chance of thunder...1 percent. Max temperature.....81-86. Min humidity........15-20 percent. Wind (20 ft)........ Slope/valley.......Light winds becoming north around 5 mph in the late morning and afternoon. Ridgetop...........West 5 to 10 mph. Mixing height.......10500 ft AGL. Transport winds.....North 5 to 10 mph shifting to the west in the afternoon. $$ Forecaster...Glinskas Requested by...Zack L Type of request...WILDFIRE .TAG 2520265.0/TFX .DELDT 08/19/25 .FormatterVersion 2.0.0 .EMAIL mthdc@firenet.gov, tfx.ops@noaa.gov