A WINTER STORM WARNING has been issued for much of central and west-central Montana from Tuesday through Thursday.
A WINTER WEATHER ADVISORY has been issued for parts of the Hi-Line.
A WINTER STORM WATCH has been issued for parts of eastern, southern and western Montana.
A major snowstorm with record cold will sweep across most of Montana through this week into the weekend. Some parts of the state will see more than a foot of snow and overnight lows could drop below zero by late this week. Now is the time to get last minute preparations ahead of this storm. A little snow will fly up around the East Glacier area through the night into early Tuesday. There will be a few rain showers in the lower elevations. A cold front will move south through the state early on Tuesday with falling temperatures and increasing precipitation. Snow will develop through the morning farther north up along the Hi-Line, with snow increasing through the afternoon for places like Great Falls, Helena and Lewistown. At the onset of precipitation, a little rain could mix with the snow but it will be brief. The storm will predominantly produce snow for most of the state. Highs on Tuesday will range from the 30s to the 40s, but temperatures will drop through the afternoon. While road surfaces are fairly warm, air temperatures will be cold enough for snow to stick on the roads certainly by dark Tuesday evening. Snow will be moderate and heavy through Tuesday night into Wednesday. Temperatures will fall into the 10s and 20s. Snow will continue across most of the state on Wednesday with highs mainly in the 20s. The snow will ease up somewhat Wednesday afternoon before another surge of snow moves in for Thursday. Again the snow will be widespread, accumulating several inches. Highs will only top out in the 10s and 20s. The storm system will pull away Thursday night, and lows will fall to near record levels in the -0s and 0s. Friday will be partly to mostly cloudy with a few light flurries or snow showers, but there will not be any additional accumulation. By Friday morning most of the state will have between 6-12", with some of the higher terrain and areas out around Lewistown that could top 18". Friday will be cold with highs in the 10s and 20s and lows that night will again fall to near record lows in the -0s and 0s. Fortunately there does not appear to be much wind with this storm system as the snow falls. Wind woes will come later in the weekend. Saturday will be partly to mostly sunny with light wind and highs in the 20s. Sunday will be mostly sunny and cold with highs in the 20s to around 30. Wind will be calm in the valleys but start to pick up along the Rocky Mountain Front and out across north-central Montana. Blowing snow will likely be an issue as wind increases to 30-35mph even in places like Great Falls. Monday will be partly cloudy with slightly warmer temperatures in the 30s. The wind will be light or calm in the valleys like Helena, but blowing snow will be a problem up on the Continental Divide, off the Rocky Mountain Front and out across central Montana. Halloween is Tuesday and warmer temperatures will move in. Highs should reach the 40s for most. While it won't be bitter cold, the warmer temperatures should make for some sloppy and slushy trick or treating.