Tornado Terror: Ohio Valley's Severe Weather Outbreak , Sud

CNN - The threat of a severe weather outbreak is growing as tens of millions of people across the eastern half of the United States face down severe thunderstorms capable of damaging wind gusts, dangerous hail and destructive tornadoes.

“A potentially substantial severe weather outbreak – possibly including a few significant/long-track tornadoes – is anticipated this afternoon and evening,” the Storm Prediction Center warned Tuesday morning.

Dangerous storms were already ongoing Tuesday morning in the Ohio Valley with numerous tornado and severe thunderstorm warnings issued, but a new round will fire up Tuesday afternoon and evening, presenting the greatest risk for destructive weather.

The storms pose the most significant threat for tornadoes so far this year, with parts of Ohio, Kentucky and Indiana most at risk. Ohio hasn’t been warned of a tornado threat this substantial in more than 10 years, according to SPC data. It’s in this region where strong tornadoes could form and stay on the ground for several miles at a time.

Tornadoes are also possible outside of the area of greatest risk in a widespread area from Alabama and western Georgia north to parts of Indiana and West Virginia. Tornadoes here could reach at least EF2 strength.

All told, more than 75 million people are at risk for severe thunderstorms from the Gulf Coast to Great Lakes. Many could encounter damaging winds of 60 to 80 mph and hail ranging from the size of quarters to baseballs.

The prediction center has urged residents in the storms’ path to monitor forecasts because the areas under risk could change. “Now is the time to ensure you have a severe weather action plan in place,” it advised.

Over 17 million people from Illinois to Maryland also face a flood threat from the storms, with flood watches lasting into the evening and rainfall totals of up to 5 inches possible.

The same severe weather system tore through the central US on Monday, prompting more than 100 storm reports across the region, including three tornadoes in Oklahoma. Homes were damaged by the storms in Barnsdall, Oklahoma, around 40 miles north of Tulsa, town police told CNN.

“I was on duty and patrolling the streets when it came through,” Barnsdall officer Eric Sofian said. “There was a lot of heavy wind, a lot of lightning and I could see a lot of sparks flying from the power lines.”

Massive hailstones were reported in Texas, including one as large as 4.5 inches in Briar – bigger than a softball.

The tornado threat will lessen Wednesday as storms shift east, but there is still a Level 2 of 5 risk for severe thunderstorms with damaging winds and hail in parts of the mid-Atlantic and Florida.
Significant snow coming
Rain north of the severe weather will transition to snow and a wintry mix later Tuesday in areas of the Midwest and Great Lakes, and rain and snow showers will continue in parts of both regions through Thursday.

Cities including Chicago could even see a few flakes, but little accumulation of snowfall is expected.

The highest snowfall totals are expected across the parts of Michigan and Wisconsin, where snowfall of 6 to 12 inches is possible through Thursday. Snowfall could snarl travel in the region.

Winter-like weather will shift into the interior Northeast beginning Wednesday, where winter storm watches are in effect for much of the interior region into Friday.

The Adirondacks could see up to a foot of snowfall by Thursday, while parts of the Green and White Mountains can see over a foot of snowfall. Gusts up to 50 mph combined with heavy snowfall can cause blowing snow and can cause power outages and travel delays.

Major cities across the Northeast, including New York City, Boston and Philadelphia, are currently forecast to see rain.