(CNN) Six people have died as a result of a severe storm system that caused blizzard conditions in the US Midwest and torrential rain and flood threats in the South.
The system dumped about a foot of snow in the Dakotas, Nebraska and Minnesota by Friday morning. It was forecast to bring heavy rain farther east Friday and cause messy travel conditions.
More than 11 inches of rain fell across some areas of Louisiana and Mississippi, where flash flood emergencies were issued overnight into Friday morning. More than 50 million people remained under flood and flash flood watches from Louisiana to New Jersey.
The snow across the northern Plains and upper Midwest was expected to wind down throughout Friday morning, but blowing snow was limiting visibility.
The storm system has caused major headaches for holiday travelers heading into the New Year's weekend.
Heavy rain and strong winds will combine to make travel difficult by air or road Friday in the parts of the East. Major delays are expected at airports in major cities such as New York, Philadelphia and Atlanta.
Snow is forecast only in northern New England.
At least 11 inches of rain fell in areas of Washington Parish, Louisiana, and Walthall County, Mississippi, according to the National Weather Service office in Slidell, Louisiana.
Weather service meteorologist Bob Wagner told CNN the weather system stalled in that area for five or six hours.
A 58-year-old woman in Ponchatoula, Louisiana, died after a tree fell on her camper trailer Wednesday night, Tangipahoa Parish Sheriff Daniel Edwards told CNN affiliate WDSU in New Orleans.
Coastal parts of Texas were walloped Thursday after severe weather caused in-flight injuries and canceled a football game a day earlier in the Dallas area.
A woman on a camping trip in Tennessee with two men died after they tried to cross a creek, according to CNN affiliate WTVC.
"The water came up," said Steve Lamb, director of the Marion County Emergency Management Agency. "Apparently they spent the night in the cave or somewhere in that area and then they tried to come out early this morning."
Lamb told WTVC the group probably didn't realize what they were getting into in the dark.
"This was a flash flood type of situation," he said.
In addition, whiteout conditions in parts of the Midwest caused road closures and travel delays.
Kansas State Highway Patrol reported a weather-related death on Interstate 70 near Oakley. The crash involved a commercial vehicle and a passenger car, Trooper Tod Hileman said.
About 1 million people were under blizzard warnings Thursday in parts of Kansas, Nebraska, Minnesota and the Dakotas, CNN meteorologist Monica Garrett said.
"Snow with high winds and low visibility will make travel in this area dangerous if not impossible at times," Garrett said.
Two people in Minnesota and one in North Dakota died due to weather conditions.
A 51-year-old man died Thursday after being hit by a private pickup truck with a plow blade in Crow Wing County, Minnesota, according to Crow Wing Sheriff Tom Dahl. Visibility was poor at the time, the sheriff's office said.
In Sherburne County, Minnesota, a 47-year-old woman died after a small bus she was on collided with an SUV on Thursday, according to CNN affiliate WCCO.
A 37-year-old man from Louisiana died in Dunn County, North Dakota, when his vehicle and another collided in "snow fog" on Thursday, according to North Dakota Highway Patrol Trooper Megan Christopher.
In Kansas, blizzard conditions closed a 75-mile stretch on I-70 from Colby to WaKeeney and roads from west of Garden City to Colorado.
Roads in parts of central and northern Minnesota were covered with ice and snow. The Minnesota Department of Transportation urged drivers to wait for conditions to improve if travel isn't necessary.
In South Dakota, snow and mixed precipitation were forecast to worsen as heavy snow combines with wind. In Nebraska, whiteout conditions and crashes forced the closure of I-80 between Lexington and North Platte.
Sharon Kay Oelkers captured video of snow blinding her town of Elwood, Nebraska, on Thursday morning.
"Our town has come to a complete standstill," Oelkers told CNN. "I work at the local grocery store, and even we are closed and we never close."