Montana Spring Storm Produces Heavy Snow & Severe Storms

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Posted at 5:59 PM, May 19, 2021
and last updated 2021-05-19 20:28:30-04

A WINTER STORM WARNING has been issued for the East Glacier area and the Rocky Mountain Front.
A WINTER WEATHER ADVISORY has been issued for areas of central and western Montana. This does not include the Helena Valley at this time.

Heavy snow possibly creating power outages, a soaking rain making for significant drought relief, severe thunderstorms with large hail and damaging wind, and cold temperatures impacting plants and livestock: the big spring storm is here. This storm and the expected snow will be heavily dependent on elevation. Rain has developed with snow over the higher terrain through Wednesday. Colder air will be drawn into the system with lowering snow levels through Wednesday night into Thursday morning. Thursday will be cold and sloppy with a mix of rain and snow falling across much of north central Montana and down along the Continental Divide. The snow will accumulate several inches in the lower elevations through the day along the Rocky Mountain Front and in the mountains. Travel will be difficult with the wet snow sticking on road surfaces in the mountains.The lower elevations like Helena, Great Falls and Townsend will start out with rain that will transition to snow. There may even be a back and forth period where it seems Mother Nature can't make up her mind. Northeast Montana will have a mix of clouds and sun with strong to severe thunderstorms developing later in the day. Besides heavy rain and lightning, severe storms could contain large hail and damaging wind. Temperatures will be much colder for western and central areas, only in the 30s and 40s. The mountains will only top out in the 20s and low 30s. Eastern Montana will range from the 40s and 50s up north, but as warm as the 80s in the southeast corner. Snow levels will continue to drop down to the valleys and plains on Thursday night into Friday morning. Snow will fly Friday morning before ending later in the day. There likely will be a switch back to rain in the lower elevations before precipitation comes to an end. High temperatures will warm into the 30s and 40s, with some 50s in eastern Montana. The storm system will split on Saturday giving much of the state a break from rain and snow. Skies will be mostly cloudy, highs will be cool in the 40s and 50s. A few isolated showers and mountain snow showers are possible. Another round of rain and thunderstorms will move through on Sunday. The storm will begin pulling away on Monday with wind and areas of rain still moving through the state.

Curtis Grevenitz
Chief Meteorologist