BOZEMAN – Temperatures were a little colder today compared to Tuesday for most of SW Montana. Why? Valley inversions.
Butte is prone to valley inversions as the city is surrounded by mountains and colder air pools up in the lower end of the valley. If you climb up above the inversion temperatures were running around 10 degrees warmer on Homestake Pass and Elk Park Pass today.
Northern Gallatin county can see weak inversions this time of the year and there was a noticeable difference in temperature between Bozeman Yellowstone Airport vs Bozeman Pass. Temperatures were around 5 to 8 degrees warmer over Bozeman Pass compared to Belgrade.
Inversions not only trap colder air at the surface they also trap air pollutants so you will see haze holding over the valleys.
We hope to break the valley inversions with a weak cold front passing over Montana Thursday from Kalispell to Billings. This will bring a NW flow and a few rain or snow showers mostly north of I-90 Thursday morning. A better chance for light rain or snow will be stretched out between Kalispell to Billings and even a slight chance for pockets of freezing drizzle Thursday morning.
Warm will move in from the WSW Friday ahead of the next weather maker. This next storm system will bring increasing snow to the MT/ID state line Saturday morning and increasing snow to SW Montana Saturday night into Sunday.
This storm will likely impact travel with accumulating snow and gusty winds Sunday into Monday morning.