Large, powerful storms are forming across the United States, increasing the likelihood of severe thunderstorms over several days.
This storm has it all. Several feet of snow and blizzard conditions in parts of the Midwest and Great Lakes, roaring winds that could knock out power and raise fire weather concerns in the Plains and Rockies, and thunderstorms that could produce tornadoes and widespread damaging wind gusts.
The snowy side of the storm hit millions of people in the north-central United States the hardest early Sunday morning, with wind-driven snow causing dangerous travel. But from late Sunday into Monday, more than 100 million people in the eastern half of the country will face an increasingly severe risk of thunderstorms.
There is a risk of severe Level 3/5 thunderstorms from the Great Lakes to the Gulf Coast on Sunday, with most storms expected to develop late Sunday afternoon or evening and continue overnight into Monday.
If severe thunderstorms develop into Sunday night, the most widespread threat will be straight-line wind gusts in excess of 90 mph. Some areas from the Tennessee Valley to the Great Lakes could see even stronger wind gusts of 125 mph or more as the storm begins to consolidate into a damaging line.
Tornadoes are also possible from the northern Gulf Coast into parts of Illinois, Indiana, and Ohio, some of which could be powerful and cause EF2 damage or higher.
The greatest risk for strong tornadoes lies with storms forming in parts of Arkansas, Missouri, Mississippi and Tennessee late Sunday afternoon or evening. This is when the supercell potential is at its peak.
The damaging thunderstorms are expected to move eastward overnight and reach the Appalachian Mountains and East Coast by Monday morning. Parts of it could still be severe by sunrise Monday, but the infusion of energy arriving this afternoon will give the storm new and more dangerous life.
On Monday, a severe thunderstorm risk level of 4/5 was in place from the Carolinas to the Maryland-Pennsylvania border, with a broader area under a level 3/5 risk for severe thunderstorms.
The most widespread impact of the thunderstorms is again expected to be damaging straight-line wind gusts, with wind gusts in excess of 125 mph possible in the storm from Georgia to Pennsylvania to New Jersey.
Tornadoes are also possible, with the greatest threat within the Level 4/5 thunderstorm danger area. Monday’s tornado could intensify if suitable atmospheric conditions are available.
The severe threat will rapidly weaken overnight as the storm moves off the coast and into the Atlantic Ocean.
The warmer south side of the storm is raising concerns for severe thunderstorms, while the colder north side is receiving significant amounts of snow.
The powerful storm has already dumped significant snow across a wide area from the northern Rockies to the Great Lakes since forming on Saturday.
Southern Minnesota and central Wisconsin were covered in more than 100 centimeters of snow by Sunday morning, with more snow expected. Snow will continue to fall in many parts of the Midwest and Great Lakes through Monday.
This storm could bring the heaviest snow ever to cities such as Rochester, Minnesota. About a foot of snow had fallen in parts of the city by Sunday morning, and another foot could accumulate before the storm ends. The heaviest snowfall in Rochester came from a storm in March 2005 that dumped 20 inches.
Snow totals are expected to exceed 3 feet in parts of Michigan’s Upper Peninsula by Monday night.
Marquette, Michigan, is no stranger to heavy lake-effect snow, but this storm could be one of the biggest on record. The city’s two-day storm total is the largest on record, reaching about 32 inches from a March 1997 storm. The current storm is expected to bring 2 to 4 feet of snow.
And this snow isn’t falling in a peaceful winter wonderland. Powerful winds are whipping up snow, causing dangerous whiteouts and prolonged blizzard conditions.
Severe conditions will make travel extremely dangerous and power outages may increase.
A blizzard warning was issued Sunday morning for more than 11 million people from the Dakotas and Nebraska to the Great Lakes. These warnings will remain in place until Monday for most people as the worst of the situation gradually begins to end.
