Water levels were still rising on some waterways in Kentucky and other portions of the Ohio Valley and mid-Atlantic flooded by a deadly coast-to-coast winter storm and now snow and dangerous cold is coming.

The storm killed at least 13 people – one in severe winds in Georgia, one in West Virginia and 11 in Kentucky, which took on some of the worst of the devastating flooding in the region.

Several others were missing amid “significant levels of flooding”in West Virginia, Gov. Patrick Morrisey said in a Monday morning news briefing.

More than a month’s worth of rain deluged much of Kentucky in less than 24 hours and set the deadly flooding into motion.

Even though the rain had long since stopped the situation was still active with waterways still swollen, Kentucky Gov. Andy Beshear said at a Monday news conference.

“There are still people that are in harm’s way,” Beshear said, adding the state was still in rescue mode even though they believed they had reached “many, if not most” people impacted by the floods.

“There are a couple rivers that haven’t crested yet, and that’s where the emergency operations are focused – especially in Martin County, where we may have 100-plus people we need to move to a to a safer place,” he added.

Emergency crews with the Kentucky National Guard and the Kentucky State Police performed more than 1,000 rescues Beshear said. First responders went “door to door” in flooded areas to make sure everyone was accounted for, the governor added.

More than 340 roads were closed in the state due to flooding, potentially a record amount, Beshear said.

“Widespread flooding of roads continues across much of the region,” the National Weather Service in Paducah, Kentucky, warned Monday morning. “Stream and river levels will continue to rise over the next few days in some areas, and this could cause new flooding to develop.”

Kentucky’s latest flood disaster hit two years after catastrophic flooding left 43 people dead and devastated parts of the state.

Beshear declared a state of emergency Friday ahead of the storm and on Sunday thanked President Donald Trump for approving a federal disaster declaration, making federal aid funding available to impacted areas, including search and rescue operations that will also persist throughout the commonwealth, Beshear noted.

Kentucky wasn’t the only state rocked by flooding.

Five flash flood emergencies – the most dire form of flash flood warning – were issued in parts of Virginia, West Virginia and Tennessee over the weekend.

One of these emergencies occurred when floodwater breached a levee in Tennessee’s Obion County Sunday. The county was under a state of emergency with mandatory evacuations in Rives, Tennessee, Obion County Mayor Steve Carr said.

The situation could unfold in more areas in the coming days as river levels continue to rise in impacted areas.

Flooding in parts of Virginia mixed with recently fallen snow and ice and worsened an already incredibly dangerous situation by adding in a hypothermia risk for anyone caught in frigid water. It’s a risk that’ll become more widespread as temperatures plummet this week.

In Indiana, drone images showed homes and roads submerged in floodwaters amid snowy weather Sunday. “It floods down here every year but it’s been awhile since it has been this bad,” said Hardinsburg resident Shelby Sandlin in a Facebook post.

The same storm that unleashed deadly flooding also brought dangerous severe thunderstorms to the South, heavy snow in parts of the Great Lakes and Northeast and powerful wind across the East.

One person died in the Grove Park area of Atlanta overnight Sunday when a large tree fell on a home amid “tremendous thunderstorm activity” in the area, Atlanta Fire Rescue Capt. Scott Powell said Sunday. Fire officials found the person trapped inside the house upon arrival around 5 a.m., he said. But the person ultimately died, Powell added.

The storm also knocked out power to more than 500,000 homes and businesses. More than 300,000 remained without power Monday morning, according to PowerOutage.us.

Hard-hitting winter storm and brutal Arctic cold to come

Frigid Arctic air started to seep into the northern US on Monday and is just the beginning of a widespread, brutal blast of record-breaking cold to come this week.

Life-threatening cold will grip nearly the entire central US starting Tuesday as both air temperatures and wind chills plummet from the Canadian border to the Gulf Coast.

Gusty winds may drive wind chills as low as 60 degrees below zero in the Northern Plains on Tuesday morning and below freezing across parts of Texas, Oklahoma, Arkansas and Tennessee.

In the Kansas City area, temperatures will remain below freezing all week, and cities such as Dallas and Houston will see double-digit temperature drops from Tuesday to Wednesday.

Wind chills in the teens and single digits will reach Kentucky by Tuesday morning and could drop below zero in parts of the state by Wednesday morning. The sudden onset of cold will coincide with yet another disruptive winter storm.

A winter storm forming over the Rockies on Monday will strengthen in the Plains on Tuesday and sweep over the South through Wednesday.

A widespread 4 to 10 inches of snow will bury parts of Kansas, Missouri and Illinois while much of Kentucky gets 3 to 6 inches of snow.

South of the snow zone, ice is forecast for cities such as Oklahoma City and Little Rock. The storm will then move into the Mid-Atlantic, including areas battered by recent storms.

Arkansas Gov. Sarah Huckabee Sanders declared a state of emergency Monday ahead of the storm’s arrival in the state.

CNN’s Nic F. Anderson, Chris Boyette, Dalia Faheid, Zoe Sottile, Zenebou Sylla, Karina Tsui, Emma Tucker, Hanna Park, Sara Smart and Graham Hurley contributed to this report.