Isaac turned into an 80-mile-per-hour Category 1 hurricane Tuesday and took aim at southeastern Louisiana, leaving health and flood warnings in its wake in South Florida.

At 5 p.m., Hurricane Isaac was “getting better organized as it nears southeastern Louisiana,” The National Hurricane Center advised. Meteorologists put the storm 105 miles south-southeast of New Orleans and 30 miles south-southwest of the mouth of the Mississippi River. But it was moving at 8 mph. At that rate it could reach New Orleans Wednesday morning.

“Flooding from storm surge and rainfall expected,” the Hurricane Center warned.

Isaac reached Category 1 hurricane strength with sustained winds of 75 mph at 12:20 p.m..

Rick Knabb, director of the National Hurricane Center, warned that Isaac will be a slowly unfolding event, with the strongest portion likely to be parked over the Gulf Coast for up to two days. Forecasters expect seven to 14 inches of rain across a broad area from southeastern Louisiana to the Florida Panhandle, and up to 20 inches in spots. Those estimate could rise if Isaac slows more than expected.

“When the comes ashore some time tonight, somewhere in Louisiana or Mississippi, that will not be the end,” Knabb said during an early afternoon conference call with reporters. “It will be the beginning.”

Hurricane warnings were in effect east of Morgan City, La., to the Mississippi-Alabama border as of the 11 a.m. Hurricane Center report.

It downgraded to Tropical Storm warning status the strip of land from the Mississippi-Alabama border eastward to Destin, Fl.

Health Departments in both Miami-Dade and Broward counties issued public health warnings on Tuesday morning, urging the public to avoid being bitten by mosquitoes because of mosquito-borne illness.

Tropical Storm Isaac left standing water. So the health authorities issued “Drain and Cover” alerts — advising the public to drain water accumulation in a range of places from birdbaths to gutters and garbage cans and to meantime use clothing, screen doors and safe repellants as precautions against mosquito bites.

“West Nile Virus, St. Louis Encephalitis, Eastern Equine Encephalitis and Dengue Fever are known diseases carried by mosquitoes,” said a Broward alert. “Taking appropriate precautions will help to prevent mosquito-borne diseases.”

On the upside, Isaac’s rain helped refill Lake Okeechobee, with lake levels rising three-quarters of a foot in two days.

It could continue to rise as runoff flows into the lake as well.

The National Weather Service extended a flood warning for most of Broward County and all metropolitan Palm Beach County until 8:30 p.m. Tuesday. Forecasters said the atmosphere remain moist from Isaac and more conducive to firing up afternoon thunderstorms.

On Tuesday, flood waters were still high in Central West Palm, which was the wettest spot in South Florida. Isaac dumped more than 11 inches on Northeast Broward and from five to eight inches along the coast from Homestead to Jupiter.

Robert Molleda, a weather service meteorologist, said West Palm Beach set a two-day record for rainfall with just over nine inches on Sunday and Monday — making it the soggiest August ever there — with a record 22.28 inches of rain. That broke a 1995 record of 20.12 inches.