A lopsided Tropical Storm Cristobal came ashore Sunday in Louisiana and ginned up dangerous weather much farther east, sending waves crashing over Mississippi beaches, swamping parts of an Alabama island town and spawning a tornado in Florida.

Cristobal made an afternoon landfall between the mouth of the Mississippi River and the since-evacuated barrier island resort community of Grand Isle, the storm packing 50-mph (85-kph) winds.

The storm had begun weakening as it moved inland late Sunday night though heavy rainfall and a storm surge were continuing along the Gulf Coast, posing a threat across a wide area into the Florida Panhandle.

At 11 p.m. EDT Sunday, the storm was centered about 20 miles (35 kilometers) north-northwest of New Orleans and it packed sustained 45-mph (75-kph) winds. With its drenching rains, Cristobal was expected to keep inundating the northern Gulf coast well into Monday.

In New Orleans, the question was how much rain would fall and whether there would be enough breaks in the bands of heavy weather for the beleaguered pumping system to meet its latest test of keeping streets free of flood waters.

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. Police and state transportation department vehicles led convoys of motorists to and from the island when breaks in the weather permitted.

Forecasters said up to 12 inches (30 centimeters) of rain could fall in some areas. The weather service warned that the rain would contribute to rivers flooding on the central Gulf Coast and up into the Mississippi Valley.

Cristobal was expected to be downgraded to a depression by Monday afternoon but had the potential to be a rainmaker for days. Its forecast path takes it through Louisiana on Sunday night and Monday, continuing into Arkansas and Missouri by Tuesday and heading up through Illinois and Wisconsin to the Great Lakes.

Rising water on Lake Pontchartrain near New Orleans pushed about two feet of water into the first floor of Rudy Horvath’s residence — a boathouse that sits on pilings over the brackish lake. Horvath said he and his family have lived there a year and have learned to take the occasional flood in stride. They’ve put tables on the lower floor to stack belongings above the high water.

“We thought it would be pretty cool to live out here, and it has been,” Horvath said. “The sunsets are great.

Elsewhere in south Louisiana, water covered the only road to Grand Isle and in low-lying parts of Plaquemines Parish at the state’s southeastern tip. “You can’t go down there by car,” shrimper Acy Cooper said Sunday of one marina in the area. “You have to go by boat.”

Though Cristobal was well below hurricane strength at landfall, forecasters warned that the storm would affect a wide area stretching roughly 180 miles (290 kilometers) along the Gulf Coast.

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.

Rain fell intermittently in New Orleans famed French Quarter on Sunday afternoon, but the streets were nearly deserted, with many businesses already boarded up due to the coronavirus.

Daniel Priestman said he didn’t see people frantically stocking up as in previous storms. He said people may be “overwhelmed” by the coronavirus and recent police violence and protests. They seemed “resigned to whatever happens – happens,” he said.

At one New Orleans intersection, a handmade “Black Lives Matter” sign, wired to a lampost, rattled in a stiff wind as the crew of a massive vacuum truck worked to unclog a storm drain.

The Sewerage & Water Board of New Orleans said the city’s aging street drainage system had limits, so residents should avoid underpasses and low-lying areas prone to inevitable street flooding.

Forecasters said some parts of Louisiana and Mississippi were in danger of as much as a foot (30 centimeters) of rain, with storm surges of up to five feet (1.5 meters).

“It’s very efficient, very tropical rainfall,” National Hurricane Center Director Ken Graham said in a Facebook video. “It rains a whole bunch real quick.”

Jefferson Parish, a suburb of New Orleans, called for voluntary evacuations Saturday of some low-lying communities because of threatened storm surge, high tides and heavy rain.

President Donald Trump agreed to issue an emergency declaration for Louisiana, officials said.