Overflowing rivers receded in Missouri and Illinois yesterday after flooding swamped communities and forced towns to evacuate, but forecasters warned rain-swollen waterways could menace Southern states downstream.
Rare winter floods have killed at least 28 people in the US Midwest since last weekend, most of them when they drove into flooded areas after days of downpours.
Midwest floods typically occur in the spring as snowmelt swells rivers.
Dozens have died in US storms, which also brought unusual winter tornadoes and were part of a wild worldwide weather system over the Christmas holiday period that also saw severe flooding in Britain.
More than 100,000 people were forced to evacuate their homes in areas bordering Paraguay, Uruguay, Brazil and Argentina after floods due to heavy summer rains caused by El Niño, authorities have said.
Weather is dominating conversation on social media over the holiday season after the international climate deal in Paris.
Particularly hard hit in the United States in recent days has been Missouri, which has suffered historic flooding.
Close to St Louis yesterday, the Mississippi River, the second-longest river in the United States, was falling after reaching near-record heights, the National Weather Service (NWS) said.
The Meramec River, which meanders near St Louis and empties into the Mississippi River, broke height records on Thursday, sending a deluge of water over its banks and forcing the closure of two major highways.
Both interstates 55 and 44 reopened yesterday, but many other roads remained closed in the St Louis area, state officials said, causing extreme traffic congestion.
Thousands of people evacuated from their homes earlier in the week were waiting to return to their communities and begin the process of cleaning up.
Hundreds of structures have been damaged or destroyed, local officials said.
The Mississippi River is expected to crest at Thebes, in southern Illinois, at 47.5’ (14m) tomorrow, more than 1.5’ above the 1995 record, the NWS forecast.
Towns farther down the Mississippi hoped their levees would take the strain.
Southern states including Louisiana and Mississippi are expected to be affected in the coming days, the NWS said.
Workers in Tennessee were preparing for the Mississippi River in Memphis to reach flood stage over the weekend.
“We’re moving things up high and we’ve got our generators out and got some extra water,” said Dotty Kirkendoll, a clerk at Riverside Park Marina on McKellar Lake, which feeds off the Mississippi River.
Flood warnings were also in effect yesterday for parts of Texas, South Carolina, Alabama and Kentucky, the NWS said, while major flooding was occurring on the Arkansas River and its tributaries in that state.
Louisiana Governor Bobby Jindal declared a state of emergency to prepare for flooding.
“All that water’s coming south and we have to be ready for it,” Lieutenant Governor-Elect Billy Nungesser told CNN. “It’s a serious concern. It’s early in the season. We usually don’t see this until much later.”