United States  -  A massive winter storm poised to unleash a barrage of heavy snow, treacherous ice, rain, and severe thunderstorms across a 1,300-mile swath of the United States will impact an estimated 62 million people starting Saturday afternoon and continuing into Monday.  Snow and ice so far this winter in the eastern two-thirds of the country have been limited to northern states. But this storm will break that mold and bring treacherous conditions to millions from the Plains to the East Coast, including in areas less prone to winter weather.  This powerful weather system is set to batter at least a dozen states with a potent mix of snow, ice, and blizzard conditions, accompanied by winds gusting up to 40 mph, creating treacherous travel conditions and potential power outages across a vast region.

“For some, this could be the heaviest snowfall in over a decade,” NOAA’s Weather Prediction Center warned.  And where it’s too warm for snow and ice, the storm could conjure up severe thunderstorms, including in some of the same areas still recovering from December’s deadly storms.  Major impacts, including “considerable disruptions to daily life … dangerous or impossible driving conditions and widespread closures,” are expected from this storm through Sunday in parts of the Central US, according to the Winter Storm Severity Index.  It all starts on Saturday afternoon when the storm develops in the Plains, fueled by a deep surge of moist air moving north out of the Gulf of Mexico.

It will start to spread snow, rain and an icy mix over the Plains late in the day as it strengthens and expands.

From there it will track east and spread a wintry mess into the Mississippi Valley and parts of the Midwest by Sunday morning. The storm will expand into the Ohio Valley and Southeast on Sunday and to the East Coast on Sunday night and Monday.

The regions at greatest risk are clear, but exactly who gets snow, ice or mainly rain — and how much — is still incredibly difficult to determine. Small shifts in the storm’s track could change the outcomes entirely. Some areas could start as snow but change over to an icy mix as warmer air enters the area, while other spots start as rain or an icy mix and gradually change over to snow.