(NEW YORK) -- Tornadoes brought on by severe storms on Monday left significant damage in parts of the South, namely Louisiana and Arkansas. As of Tuesday, 20 million Americans are on alert for severe storms capable of tornadoes from Baton Rouge to Atlanta into the evening.
The storms will continue to push east on Tuesday with severe thunderstorms and tornado warnings in effect from Texas to Kentucky. The big threat zone for Tuesday will be from Louisiana to Alabama and Tennessee. Cities in the path include New Orleans; Nashville, Tennessee,; Mobile, Alabama and Montgomery, Alabama.
The main threats on Tuesday are tornadoes, damaging winds and flash flooding.
A Tornado Watch remains in effect for parts of five states – Louisiana, Mississippi, Alabama, Atlanta and Tennessee. These storms will continue to progress eastward throughout Tuesday afternoon and evening – in the near term, the biggest threat for tornadoes will be across Alabama. Flash flooding will also be possible during the heaviest downpours. Atlanta will likely get hit with two rounds of severe storms.
In Louisiana, 10,000 customers are without power on Tuesday with ongoing severe storms. So far there are been four reported tornadoes across four states -- Louisiana, Arkansas, Tennessee and Mississippi.
The severe weather threat continues into Wednesday with a new round of storms from the Florida panhandle through much of Georgia. Strong wind gusts and a couple of tornadoes will be possible on Wednesday morning and into the early afternoon hours before clearing out by Wednesday night.
The northern part of the storm system is bringing more than a foot of snow and significant ice accumulation to parts of the Upper Midwest Tuesday. Some of the highest snow totals are across southeast South Dakota, west of Sioux Falls, where up to 22 inches of snow has fallen.
Additional snow and dangerous travel is expected to continue through the evening across parts of South Dakota, Minnesota, and Wisconsin.
Over a foot of snow and winds over 40 mph are possible in Nebraska, South Dakota and Minnesota Monday into Tuesday, potentially causing driving conditions and power outages.
Nearly a foot of snow had already fallen in northern Nebraska as of Tuesday morning. Up to a foot and a half of snow is still possible in parts of South Dakota and Minnesota.
Significant damage was reported in Jonesboro, Louisiana and Jessieville, Arkansas on Monday.
The local fire department is responding to numerous stranded motorists and water rescues from residences in Greenville, Kentucky, amid flash flooding. Authorities said numerous roadways are flooded inside the city and throughout our district. Numerous first responders and road crews are blocking flooded roadways.
Multiple homes were damaged in Jessieville, Arkansas, on Monday after a possible tornado passed through the area, law enforcement officials told ABC News.
Garland County Sheriff's Office Deputy Courtney Kizer said 14 homes were damaged, with at least two homes so severely that several families would not be able to live in them again.
A tornado watch was issued for portions of the South, including parts of eastern Texas, northwestern Louisiana and much of Arkansas on Monday.
One of those destroyed homes was across the street from Jessieville High School, which had seven of its buildings damaged.
Students were in class at the time and were directed to go to their "safe rooms," Kizer said.
Three commercial buildings in Jessieville were also damaged. No injuries were reported.
Thunderstorms will develop ahead of a cold front making its way through southeast Texas late Monday night into Tuesday morning, according to the NWS.
Additionally, the storms could also produce flash flooding through Monday night. Flood watches are in effect.
By Tuesday, the severe storms will shift east across Mississippi and Alabama, with flooding and damaging winds possible from New Orleans to Montgomery, Alabama.
The same storm system that brought flooding to California over the weekend has now moved into the Central U.S., bringing the winter storm to the North and the severe weather and flooding to the South.
At least 22 states, from California to Indiana, are under alert for heavy snow, dangerous ice, high winds and flooding rain.
More than 3 feet of snow fell in the Sierra Mountains in California over the weekend. According to the UC Berkeley Central Sierra Snow Lab, up to 7.5 inches of snow fell per hour on Saturday in the Sierras.
Major atmospheric river storm to arrive in California
The California coast is preparing for an inundation of heavy rainfall with the next atmospheric river set to flood parts of the state from Wednesday morning to Thursday morning. The National Weather Service warned it will be an impactful storm and needs to be taken seriously.
The first round of rain moves into the Bay Area and Northern California on Wednesday morning when winds are expected to pick up. The second, even heavier round of rain and the major threat for flooding will be Wednesday during the late afternoon and evening, when the worst of the flooding rain and damaging winds gusts will occur.
By Thursday, heavy rain is expected to move into Southern California and the Los Angeles area. Although the worst will be over for the Bay Area, lingering rain will continue across the region, which will likely create issues even after the big event.