A winter-like spring storm pounded the USA's midsection on Sunday, covering the Upper Midwest in heavy snow and ice while whipping farther south, bringing high winds and even tornadoes. 

The combination of snow and wind grounded hundreds of flights, closed highways and canceled Major League Baseball games and church services. And Mother Nature's April surprise that packed a deadly punch from the Gulf Coast to northern Wisconsin and Michigan isn't over yet. More snow is possible from two storm systems that could bring more severe weather in the week ahead.

On Sunday, heavy snow fell from the Upper Midwest to the Upper Great Lakes with a chance of rain and freezing rain from the Great Lakes to the Northeast, according to the National Weather Service. Heavy rain was possible from the Mid-Atlantic to parts of the Tennessee Valley. 

Southern Minnesota, including the Twin Cities, could get up to 20 inches of snow, the weather service said.

Dangerous conditions continued in the Milwaukee area, where snow and freezing rain wreaked havoc on roads, caused power outages and made roofs collapse. The storm, on track to become the biggest to hit northeastern Wisconsin in April, could dump an additional 8 to 15 inches of snow on the Green Bay area, which got nearly a foot of snow on Saturday, according to the Milwaukee Journal Sentinel.

Officials say no one was hurt when heavy snow caused part of a hotel roof to collapse in northeastern Wisconsin. WLUK-TV reported that the roof fell in over the pool Sunday at an Econo Lodge Inn & Suites in Ashwaubenon, near Green Bay.

Numerous flights at Austin Straubel International Airport in Green Bay were canceled Sunday, the newspaper reported. At Appleton International Airport, plow drivers worked all weekend to keep runways open.

Green Bay was forecast to remain under a snow emergency until 5 a.m. Monday. 

Difficult travel conditions in northeastern Wisconsin through the weekend should begin to ease Sunday night, according to the weather service.  

Many highways across the region were covered in ice or snow on Sunday, according to the state Department of Transportation.

In a Facebook post, the Outagamie County Sheriff's Department said officers were describing the blizzard using terms such as "worst storm ever."

"It's probably going to go in the record books as a historic April snowstorm," Roy Eckberg of the National Weather Service told the Journal Sentinel.

Some 200 Sunday flights were canceled at the Minneapolis-St. Paul International Airport, where two runways were open but nearly 13 inches of snow and strong winds were making it difficult to keep runways open and planes de-iced, spokesman Patrick Hogan told the Associated Press. On Saturday, more than 400 flights at the airport were grounded by the storm.

The Minnesota Twins home games against the Chicago White Sox were called off as more than 13 inches of snow blanketed Minneapolis. The New York Yankees and Detroit Tigers were rained out Saturday in Detroit. Several highways in southwestern Minneapolis were closed.

Winds up to 55 mph whipped waves on Lake Michigan in Wisconsin and Illinois that could reach as high as 18 feet, causing potential coastal flooding. People gawking at the giant waves along Lake Michigan and Lake Superior were warned to stay off break walls to avoid being swept away, the Journal Sentinel reported.

Freezing rain cut power to nearly 160,000 homes and businesses across Michigan, as the winter storm warning remained in effect for most of the state. Residents were being urged to remain home with roads expected to become impassable later Sunday. Heavy rain caused severe flooding in some areas, the Detroit Free Press said. 

South Dakota got a bit of storm relief on Sunday, allowing the airport in Sioux Falls to reopen for the first time since Thursday, according to the AP.

Tornado watches were in effect in parts of Florida on Sunday as the severe storms in the central United States brought high winds, lightning and heavy rains to the deep South.

A tornado caused some damage in parts of Louisiana and Mississippi. Winds up to 115 mph touched down Saturday night in Meridian, Miss. knocking out power and uprooting trees, the weather service said. 

Another tornado ripped through Richland Parish near Rayville, La., on Sunday afternoon but caused only minor damage.

In North and South Carolina, about 75,000 homes and businesses were without power in the late afternoon. Storms downed trees, pelted communities with hail and caused airport delays, according to the AP.

A new storm system was forecast to bring rain and mountain snow to the Northwest and Northern California on Sunday, spreading to the northern Rockies by Monday.

Snow or a mix of rain and snow will sweep through the northern Plains into the upper Mississippi Valley and much of the Great Lakes through Wednesday.

There have been at least three storm-related deaths. Two people died Saturday. In Louisiana, a toddler was killed when the storm blew a large tree onto her family's mobile home. Authorities in Wisconsin said a woman there was killed when she lost control of her minivan on a slush-covered highway and slammed into an oncoming SUV.

On Friday, a truck driver from Idaho died when he lost control of his rig on the snow-covered highway in western Nebraska and struck a stranded tractor-trailer.

In Texas, hail the size of hen eggs fell south of Dallas, meteorologist Patricia Sanchez told the AP. Strong winds in Austin spread the flames from a lightning strike, damaging two houses. In Texas and Oklahoma, the National Weather Service issued a "red flag" warning because of extremely high fire danger.