(Reuters) - The remnants of Hurricane Isaac brought rain to drought-stricken parts of the lower U.S. Midwest on Saturday after the storm killed at least 30 people on its trek across the Caribbean and Louisiana and Mississippi, authorities said.
Rainfall totals of no more than 3 inches were expected through the lower Ohio River Valley by Saturday night after Isaac lost much of its punch while passing over Missouri.
Top sustained winds had dropped to 20 miles per hour and flash flood threats were diminishing, the National Weather Service said.
Flood warnings were still in effect for the Kansas City, Missouri, area as well as south-central Illinois, but Dan Petersen, a forecaster at the National Weather Services' Hydrometeorological Prediction Center in College Park, Maryland, said flooding was not expected to pose much of a problem.
"The rain is going to be occurring in areas that are parched and have greater capacity for accepting rainfall," Petersen said.
At least five deaths in Louisiana and two in neighboring Mississippi were blamed on Isaac and residents of the two states still suffered from power outages and widespread flooding on Saturday, authorities aid.
President Barack Obama, who declared a disaster in Mississippi and Louisiana on Wednesday, is scheduled to visit the region on Monday.
Isaac was the first hurricane to strike the United States this year and it hit New Orleans almost exactly seven years after Hurricane Katrina devastated the city, causing an estimated 1,800 deaths.
More than 500,000 homes and businesses remained without electricity across Louisiana on Saturday, leaving them without air conditioning under sweltering temperatures, local government officials said.
In other lingering effects from the storm, U.S. regulators said 93 percent of daily oil production and 65 percent of national gas output in the U.S.-regulated part of the Gulf of Mexico remained shut on Saturday due to Isaac.
Producers returned only a small amount of crude oil production by Saturday, while the return of natural gas production was also proceeding solely, according to U.S. regulators. Many producers said they continued restaffing offshore platforms and production was expected to ramp up quickly in the coming days.
Isaac lingered over New Orleans for the better part of two days, providing a first, successful test of the city's $14.5 billion flood-control system assembled after Katrina. Areas outside those flood protections fared worse.
At least one levee was overtopped southwest of New Orleans, leaving some homes under 12 feet of water. New Orleans was struck by 20 inches of rain, and many other locations in Louisiana and Mississippi logged more than 10 inches of rain.
Isaac was expected to be a mixed blessing for the drought-parched Midwest farm belt, since experts said its rains came too late for this season's crop of corn and most soybeans.
The worst drought in nearly half a century remains deeply entrenched across nearly two-thirds of the United States.
Isaac's rains could help speed up pasture recovery, however, and get the U.S. winter wheat crop off to a good start.
The U.S. Department of Agriculture is to release estimates on Tuesday of Isaac's damage to cotton and rice crops in the Mississippi Delta and lower Mississippi Valley region.
Isaac killed 23 people in its passage over Hispaniola, the Caribbean island shared by the Dominican Republic and Haiti, before barreling into the U.S. Gulf of Mexico.
On the heels of Isaac, Tropical Storm Leslie churned over the open Atlantic Ocean on Saturday, hundreds of miles east-northeast of the Caribbean's Leeward Islands.
Leslie had top sustained winds of 70 mph. But U.S. forecasters said it posed no immediate threat to land and was not expected to become a hurricane before veering away from the Caribbean and heading farther out to sea in s north-northeast direction on Tuesday.
Reporting by Tom Brown and David Bailey; Writing by Tom Brown; Editing by Vicki Allen and Peter Cooney