A RED FLAG WARNING remains in effect through most of Montana tonight and into Thursday evening.  Increasing thunderstorm activity this evening with erratic outflow wind, and then continued hot temperatures, low humidity, and strong wind will keep the fire danger extreme into the holiday weekend.  Chance of ignition is nearly 100% because of how dry fuels are right now.  Lightning this evening and a few isolated thunderstorms tomorrow could produce new wildfires.  After Thursday, thunderstorms dry up but the wind will really pick up.  Humans are more likely to be that ignition source after Thursday.  If there is a small silver lining, the wind increasing will at least mix out some of the smoke and poor air quality.  An AIR QUALITY ALERT is in effect for western Montana until Thursday morning.  After that, west wind will likely lower the smoke concentration some.  This wind will also promote fire growth in the afternoons, so the smoke pattern will become such that air quality improves in the afternoon, but increasing fire behavior will put more smoke in the atmosphere that will settle closer to the ground in the morning hours when the wind eases.  Temperatures will be hot through the end of the workweek, and into Labor Day weekend.  Highs will be in the 90s for most locations, and with humidity in the 7-20% range with wind up to 25mph, the fire danger will remain piping hot.  Sunday’s highs could reach the upper 90s to around 100 with west wind peaking over 30mph.  A dry cold front will bring cooler temperatures and a wind shift to the north on Labor Day.  Highs will be in the 70s to around 80, with north wind up to 20mph.  The wind shift could temporarily blow smoke out of the area.  However, hot and dry weather will continue into the middle of September.

Please remember all campfires are prohibited this weekend.  We do not want to spark any new wildfires!

Curtis Grevenitz

Chief Meteorologist

Story continues below