MISSOULA — A river of atmospheric moisture will continue to bring heavy mountain snow and valley rain/snow Wednesday.
An Avalanche Warning has been issued for the Southern Swan, southern Missions, Rattlesnake, and the central and southern Bitterroot mountains through 6 am Thursday. New heavy snow, warm temperatures and strong winds are creating very dangerous avalanche conditions. High temperatures will be well above average Wednesday as highs top out in the upper 30's to middle 40's.
Snow levels will begin to drop this afternoon as a cold front moves through the northern Rockies. Models are showing the potential for snow bands to develop this afternoon. The exact location of these bands remains uncertain, however, those traveling over Lolo, Lookout, and Lost Trail passes look to have the best chance to see these snow bands develop.
Snow levels drop to valley floors tonight into Thursday morning. West-central and southwest Montana look to have the best chance to see light accumulating snow fall in the valleys starting Wednesday night and lasting through Thursday morning.
Snow will gradually come to an end by late morning or afternoon Thursday. However, this break won't last long as another system and associated warm front will bring snow to all elevations Thursday night into Friday morning. Snow will generally decrease through the day Friday as temperatures once again warm into the 40's any lingering valley precipitation will turn to rain through the day.
Active weather remains for the weekend as yet another system brings valley rain/snow and mountain snow Saturday. Expect temperatures in the upper 30's to low 40's Saturday, with a cold front dropping temperatures back into the low 30's Sunday.