Parts of Kansas and Pennsylvania are recovering from another terrifying evening of tornadoes -- the 13th consecutive day that twisters have struck the US -- and millions of people still are at risk of more severe weather on Wednesday.
A massive, rain-wrapped tornado ripped by Linwood, Kansas, outside Kansas City on Tuesday evening, and dozens of homes on Linwood's outskirts are "all gone," Mayor Brian Christenson told CNN.
At least one tornado and severe storms ravaged areas there and in nearby Douglas County, Kansas, destroying stretches of homes and businesses. At least 12 people were injured in the severe weather, officials said.
The tornado near Linwood leveled Brian Hahn's home while he and his family were huddled in the basement under a mattress.
"I could hear it was over us and I saw my bedroom just leave," he told CNN affiliate KMBC. "It was gone."
"I feel lucky I'm alive."
To the northeast, another tornado was confirmed by the National Weather Service in Berks County, Pennsylvania, "based on video received showing a tornado on the ground." It moved through the area Tuesday evening.
Morgantown was one of the hardest-hit areas in the county, but no one was injured there, Caernarvon Township Police Chief John Scalia told CNN affiliate KYW.
"When you drive around, see the destruction, you realize how lucky we are nobody was hurt," Scalia said.
More than 39 million people are under an enhanced risk of severe weather Wednesday in two areas. One ranges from Texas into Illinois, and includes the cities of Dallas and St. Louis.
The other stretches from the eastern Ohio River Valley into Pennsylvania and the Mid-Atlantic coast, and includes the cities of Philadelphia, Baltimore and Washington.
Some places will see 'record-breaking' flooding
Rains this week are exacerbating flooding that has troubled parts of the central US for weeks.
While flooding has occurred for days along the Arkansas River in Oklahoma, the river is now approaching record levels to the east, in Arkansas itself.
In western Arkansas near the communities of Van Buren and Fort Smith, the Arkansas River is expected to crest Wednesday afternoon at around 41 feet -- roughly 3 feet above the record there.
"This is looking to be record-breaking all along the Arkansas River, and this is something we have never seen before," Arkansas emergency management spokeswoman Melody Daniel said.
Levees along the river in Arkansas have worked so far -- water has overtopped two of them, but they have not failed, Daniel said.
Daniel said more than a dozen Arkansas counties are expected to see historic flooding: Sebastian, Crawford, Logan, Johnson, Yell, Pope, Perry, Conway, Faulkner, Pulaski, Jefferson, Lincoln and Desha County.
Officials in the central Arkansas city of North Little Rock, across the river from the state capital, believe 50 homes could soon be impacted by flooding, the city said in a Facebook post Tuesday.
"Respect all barricades and road and trail closures," the city posted. "They are there for your protection. Do not put our emergency responders in a position that would be dangerous to you and them."
In Ozark, Arkansas, the river will likely break its record Thursday before it crests Friday, CNN Meteorologist Michael Guy said.
"The last crest to break the record was in 1943," he said. "The last time the river was this high at this location was 1990."
Flooding near the site already occurred once this year, in early January.
One person was killed in Arkansas Tuesday evening after drowning in flood waters, police told CNN.
The victim, a 64-year-old man, had been driving a small Suzuki SUV, Barling police officer James Breeden said.
Authorities said the vehicle appeared to have driven into a flooded roadway that had been barricaded. A deputy sheriff saw a body floating in the water and attempted a rescue, Breeden said. The man's body was located near Fort Chafee.
Further north, officials are warning of fast rises on the lower Des Moines River in Iowa and on the Fox River in northeastern Missouri. Both are expected to reach major flood stage -- which could lead to flooding -- by Wednesday.
More than 500 tornado reports in 30 days
The National Weather Service has received more than 500 tornado reports across the country in the last 30 days -- an unusually high amount.
There are only four other recorded instances when more than 500 US tornadoes were observed in a 30-day period: in 2003, 2004, 2008 and 2011, according to Patrick Marsh, a meteorologist with the weather service's Storm Prediction Center.
Tuesday was the 13th straight day of tornadoes in the US -- and the jet stream played a part in the last two weeks, CNN meteorologist Chad Myers said.
"It is a stuck jet stream," with areas of low pressure riding along it, Myers said.
The jet stream will finally shift by Thursday, and the risk for severe weather in the US will greatly diminish for at least the next week, Myers said.
Record-breaking May rains
Tuesday's rain broke records in Kansas City, the National Weather Service said.
The city received 1.56 inches of rain, boosting the monthly total to 12.81 inches. The city's previous record for May was set in 1995 at 12.75 inches.
"This also makes this May the 3rd wettest month for ANY month in (Kansas City's) 131-year period of record," the weather service tweeted.