Tropical storm Isaac has officially turned into category one Hurricane Isaac. The U.S. National Hurricane Center in Miami said Isaac became a Category 1 hurricane Tuesday with winds of 75 mph and could get even stronger.

While residents in southeast Louisiana prepare for the weather system to make landfall nearby on Tuesday night or early Wednesday, President Barack Obama said Gulf Coast residents should listen to local authorities and follow their directions as Isaac approaches.

"Now is not the time to tempt fate. Now is not the time to dismiss official warnings. You need to take this seriously," Obama said.

Harrison County, Mississippi, which already has issued a curfew from this evening through Wednesday morning, is now ordering evacuations in low-lying areas, CNN affiliate WLOX-TV reports.

In addition, a tornado warning was issued for some areas in Southeastern Louisiana, including Orleans Parish, St. Tammany Parish, Slidell and Eden Isle, according to the National Weather Service. Southwestern Hancock County in Mississippi is also included.

Richard Knabb, director of the National Hurricane Center, took to the NHC website to inform Gulf Coast residents that despite concerns about the Isaac's winds, a storm's "water components are often the more deadly and sometimes the more damaging."

Knabb says that with Isaac's potential storm surge of 6 to 12 feet in some areas and its ability to dump up to 20 inches of rain as it slows down over land, there is an increased threat of inland flooding in the next few days.

"It's not just going to be a coastal event," he said.

Hurricane Isaac was last recorded about 160 miles from New Orleans as of 11:20 a.m. Tuesday, with its central pressure lowering to 975 mb, which leads to stronger winds. It is the fourth hurricane of the 2012 Atlantic season.

President Barack Obama signed a disaster declaration for Louisiana, which opens the valves on federal aid to the state. "We are dealing with a big storm, and there could be significant flooding and other damage across a large area," Obama said.