BOZEMAN – A quiet weather pattern today with High-pressure building over the region producing sinking stable conditions. This type of pattern does strengthen valley inversions especially west of the divide and those cold pools can trap colder air and pollutants down into the lower valleys.
The forecast is looking cool and dry for trick or treating tonight across SW Montana. After sunset temperatures will fall below freezing.
There is an Air Stagnation Advisory up for most of western Montana through midnight Wednesday.
The next weather maker is a couple of weak disturbances that will bring increasing rounds of moisture over the region beginning Thursday into Friday and another system on Sunday.
These will be warmer storm systems and that means valley rain is possible with much higher snow levels.