MISSOULA — A low pressure system will bring valley rain and mountain snow to the forecast Tuesday. The one exception will be for valleys along the divide (Seeley Lake, Butte, Philipsburg) where these locations could see a rain/snow mix or even some freezing rain before temperatures warm up. For mountains and mountain passes above 5,000 feet, periods of light to moderate snow are anticipated especially along the Continental Divide in northwest Montana.
By late afternoon and evening a Canadian cold front will move from east to west across the Divide. This front will allow snow levels to drop to valley floors overnight Tuesday into Wednesday morning. As the front moves through expect a period of possible light accumulating snow for most locations late tonight. Snow covered roads or icy roads will be possible Wednesday morning as colder air moves into the region.
Right now winter weather highlights are in effect for locations along the Continental Divide, however, these could extend further west to account for slick roads tonight through Wednesday morning. Here is a look at the latest Watches and Warnings:
Winter Storm Warning:
West Glacier Region above 3,500 ft (8 am to Midnight Tuesday): 5"-to-10" This includes Marias Pass
Winter Weather Advisory:
West Glacier Region (8 am to Midnight Tuesday): 1"-to-2" this includes Bad Rock Canyon, Essex, Highway 83 Bigfork to Swan Lake and Polebridge
Butte/Blackfoot Region (8 am to Midnight Tuesday): 1"-to-3" this includes Butte, Philipsburg, Georgetown Lake, Highway 12 Garrison to Elliston, Homestake Pass and MacDonald Pass.
Seeley Lake/Potomac Region (8 am to Midnight Tuesday): 1"-to-3" this includes Highway 200 Bonner to Greenough, Highway 83 Seeley Lake to Condon and I-90 East Missoula to Bearmouth
A ridge of high pressure will build over the northern Rockies Wednesday through Saturday. Expect sunshine with temperatures in the 30's Wednesday and Thursday with highs retunring to the 40's Friday and Saturday.