Tropical Storm Cristobal could soon renew its strength by merging with another storm system to form a large cyclone, forecasters say.
After drenching much of the South, forecasters now expect the storm to bring fierce winds and heavy rain to much of the Midwest by Tuesday.
A very strong storm system sweeping out from the Rocky Mountains is expected to collide with Cristobal in the next couple of days, said Greg Carbin, chief of operations at the National Weather Service’s Weather Prediction Center in College Park, Maryland.
â€œThe two will eventually merge into a large cyclone,” Carbin said. â€œItâ€™s a pretty fascinating interaction we’ll see over the next couple of days.”
Wind gusts of up to 45 mph (72 kph) are expected in Chicago by Tuesday night, the National Weather Service said. Boaters were being warned of gale-force winds on nearby Lake Michigan on Tuesday and Wednesday.
Cristobal weakened into a depression early Monday after inundating coastal Louisiana and ginning up dangerous weather along most of the U.S. Gulf Coast, sending waves crashing over Mississippi beaches, swamping parts of an Alabama island town and spawning a tornado in Florida.
Heavy rainfall and a storm surge continued posing a threat across a wide area of the coast after Cristobal made landfall Sunday afternoon packing 50-mph (85-kph) winds between the mouth of the Mississippi River and the since-evacuated barrier island resort community of Grand Isle.
At 10 a.m. CDT Monday, the storm was centered about 15 miles (30 kilometers) east of Monroe, Louisiana, with top winds of 35 mph (55 kph). It was moving northwest at 15 mph (24 kph).
Cristobalâ€™s remnants could be a rainmaker for days. Its forecast path takes it into Arkansas and Missouri by Tuesday, then through Illinois and Wisconsin to the Great Lakes.
â€œItâ€™s very efficient, very tropical rainfall,â€ National Hurricane Center Director Ken Graham said in a Facebook video. â€œIt rains a whole bunch real quick.â€
In their last update on Cristobal from the hurricane center, forecasters said up to 15 inches (38 centimeters) of rain could fall in some areas, and could cause significant river flooding across the mid and upper Mississippi Valley.
Coastal Mississippi news outlets reported stalled cars and trucks as flood waters inundated beaches and crashed over highways. On the City of Biloxi Facebook page, officials said emergency workers helped dozens of motorists through flood waters, mostly on U.S. 90 running along the coast.
In Alabama, the bridge linking the mainland to Dauphin Island was closed much of Sunday but was being reopened Monday. Police and state transportation department vehicles led convoys of motorists to and from the island when breaks in the weather permitted.
The U.S. Coast Guard said it was searching for two people who went out in a 20-foot yellow boat near Slidell, Louisiana on Sunday afternoon and hadnâ€™t returned. A helicopter and local officials were assisting in the search for Ted Roach and Jennifer Lingoni, the Coast Guard said in a statement.
Elsewhere in south Louisiana, water covered the only road to Grand Isle and low-lying parts of Plaquemines Parish at the state’s southeastern tip. â€œYou can’t go down there by car,â€ shrimper Acy Cooper said Sunday of one marina in the area. â€œYou have to go by boat.â€
President Donald Trump agreed to issue an emergency declaration for Louisiana, officials said.
In Florida, a tornado – the second in two days in the state as the storm approached – uprooted trees and downed power lines Sunday afternoon south of Lake City near Interstate 75, the weather service and authorities said. There were no reports of injuries. The storm also forced a waterlogged stretch of Interstate 10 in north Florida to close for a time Sunday.
Associated Press reporters Gerald Herbert and Kevin McGill in New Orleans; Curt Anderson in St. Petersburg, Florida, and Jay Reeves in Birmingham, Alabama, contributed to this report.