By Meteorologist Mary Gilbert, CNN
(CNN) — The potential for a multi-day outbreak of severe thunderstorms is climbing as a massive, powerful storm tracks across the United States.
This storm has everything: feet of snow and blizzard conditions for parts of the Midwest and Great Lakes, roaring winds capable of knocking out power and elevating fire weather concerns in the Plains and Rockies, and thunderstorms that could unleash tornadoes and widespread damaging wind gusts.
The storm’s snowy side packed the most significant punch early Sunday for millions in the north-central US, with wind-whipped snow creating dangerous travel. But from late Sunday through Monday, more than 100 million people in the eastern half of the country will face an increasingly severe thunderstorm risk.
A Level 3 of 5 risk of severe thunderstorms is in place from the Great Lakes to the Gulf Coast on Sunday, with most storms expected to fire up late Sunday afternoon or evening and continue overnight into Monday.
Damaging straight-line wind gusts past 60 mph are the most widespread threat with any severe thunderstorms through Sunday night. Some areas from the Tennessee Valley into the Great Lakes could see even stronger gusts of 75 mph or more as storms start to congeal into a damaging line.
Tornadoes are also possible from the Gulf Coast north into parts of Illinois, Indiana and Ohio, and some could be strong — capable of causing EF2 damage or greater.
The greatest risk of strong tornadoes exists with storms that develop in parts of Arkansas, Missouri, Mississippi and Tennessee in the late afternoon or early evening on Sunday. This is when the potential for supercells is at its peak.
Damaging thunderstorms will push east overnight and reach the Appalachians and East Coast by Monday morning. Some will likely still be severe at sunrise Monday, but an injection of energy arriving in the afternoon will give the storms a new, even more dangerous life.
A Level 4 of 5 risk of severe thunderstorms is in place Monday from the Carolinas to the Maryland-Pennsylvania border, with a wider Level 3 of 5 risk in place in surrounding areas.
Damaging straight-line wind gusts are again expected to be the thunderstorms’ most widespread impact, with gusts past 75 mph possible in storms from Georgia to Pennsylvania and New Jersey.
Tornadoes are possible too, with the greatest threat located within the Level 4 of 5 thunderstorm risk area. Any tornado on Monday has the possibility to become strong if it can tap into just the right atmospheric conditions.
Severe threats will quickly drop off overnight as storms track off the coast into the Atlantic.
Potentially historic snow, blizzard conditions
While the southern, warmer side of the storm is generating severe thunderstorm concerns, the cold northern side has been busy generating a lot of snow.
The powerful storm has already dropped a wide stretch of significant snow from the northern Rockies to the Great Lakes since first forming on Saturday.
More than a foot of snow buried parts of southern Minnesota and central Wisconsin by Sunday morning, with plenty more to come. Snow will continue through Monday for much of the Midwest and Great Lakes.
This storm could be the snowiest ever in cities like Rocheste