A WINTER STORM WARNING is in effect for most of central, northern and western Montana into Thursday.
A WINTER WEATHER ADVISORY is in effect for the lower elevations around the Helena Valley and across northeast Montana.
Arctic air is in retreat mode as most of the state is significantly warmer but widespread snow will blanket the state through Wednesday into Thursday. After an historic cold spell, temperatures have warmed by nearly 30 degrees over the last day. It feels much warmer out but the entire state is still below freezing. Arctic air will be moving back into the state as moisture moves in from the Pacific creating good conditions for widespread snow. Areas of light snow will continue in the mountains and out across the plains into Wednesday morning. Wednesday will have areas of snow that will be on and off across the state. Highs will range from the 0s again up on the Hi-Line, to the 10s and 20s farther south. Snow will become more widespread and steadier through Wednesday afternoon and evening. Most of this storm's accumulation will occur through Wednesday night into Thursday morning. Snow will quickly taper off through the early morning with sunshine increasing through the day. Highs will be cold again, only in the -0s and 0s. Thursday night's low will dip well below 0 again to as cold as -20. This is still dangerously cold, but it's not as bad as just a few days ago. This arctic outbreak will not last nearly as long as temperatures warm up into the 20s and 30s on Friday. Clouds will increase along with the temperatures. Some areas up on the Hi-Line will still have highs in the 0s but warmer air will take over the entire state this weekend. Call it a January Thaw because temperatures will warm above the freezing point for most. Under mostly cloudy skies on Saturday, highs will top out in the 30s to around 40. There may be a few isolate snow showers over the mountains. The wind will gust up to around 20mph across the plains. Sunday will be mostly cloudy with temperature in the 30s and 40s. Relatively mild weather will continue through early next week. As of now, there are no major arctic outbreaks or heavy snowstorms through the end of January.