BOZEMAN – Strong Pacific storm system is beginning to hit western Montana Saturday afternoon. A surface cold front will pass through the entire state Saturday afternoon through Sunday afternoon.
Ahead of the front strong surface wind gusts are developing both west and east of the divide but the strongest peak gusts should be along the divide eastward. For that reason, there is a HIGH WIND WARNING up across SW Montana through 9 pm Saturday.
Sustained west to SW winds around 20 to 40 mph are expected and peak gusts over 50 mph are possible with the strongest peak gusts over 60 mph in favored high wind prone areas.
The combination of above normal temperatures, very strong surface wind gusts and extremely dry surface conditions has a RED FLAG WARNING up over most Montana through 9 pm Saturday. This means new fire starts are possible and small accidental fires can grow out of control very quickly.
Once the front passes through look for a sharp temperature drop Sunday. Temperatures will fall well below normal Sunday to Monday. Good news about this storm is its packing moisture. Valley rain is possible tonight and Sunday over SW Montana but isolated to scattered showers. Mountains above 7,000’ could be covered in several inches of snow by Monday morning. Highest mountain peaks could pick up over 6” and some forecast models have up to a foot of snow at the highest elevations.
This storm system will slowly exit the region by Monday and a slow warming and drying trend will begin to redevelop starting Tuesday of next week.
The other hazard in the short-term forecast is air quality. Ahead of the front the flow aloft is out of the SW and this is paving the way for wildfire smoke to lift into SW Montana from fires as far away as California and local fires will burn actively with the current weather pattern. The flow aloft should veer out of the NW by Sunday afternoon and hopefully improve air quality.