GULFPORT --- South Mississippi is braced for the fury, and subsequent heartache, of powerful Hurricane Katrina.

Packing winds at 180 mph at mid-day Sunday, the Category 5 Hurricane Katrina is expected to make landfall around 7 a.m. today near Grand Isle, La.

This image from NOAA on Sunday shows Hurricane Katrina about 275 miles south-southeast of the mout of the Mississippi River. According to the Natinal Hurricane Center, Katrina is currently a Category 5, with maximum sustained winds near 175 mph with higher gusts. (Associated Press)

Forecasters warn that a 25-foot storm surge is possible and predict the area will experience hurricane-force winds for about 12 hours. Tropical storm winds were expected to reach the coast by Sunday eveing.

Some watching the track of Hurricane Katrina believe it will be as catastrophic, if not more so, as Hurricane Camille, the most powerful hurricane to hit land in U.S. history.

The following is an excerpt from a blog on Weather Underground.com, a Web site specializing in weather: "If the eye wall was to shrink to 15 nautical miles in diameter, we would have another Camille --- except it is a larger storm than Camille."

"If Katrina maintains a Category 5 intensity all the way to the coast, a storm surge of 24-28 feet will hit the Delta region ... this storm will produce the most catastrophic damage in modern times if it maintains its intensity and projected track. The repercussions will be felt nationwide for a very long time."

Harrison, Hancock and Jackson county officials ordered mandatory evacuations in some areas and urge other residents to leave town.

In Harrison County, mandatory evacuations for Zones A and B were effective at 10 a.m. Sunday. Flood zone maps are located on the Harrison County Civil Defense Web site at www.co.harrison.ms.us. They also are printed on page 55 of the 2005 Bellsouth phonebook.

Col. Joe Spraggins, director of the Harrison County Emergency Management Agency, strongly urges all Harrison County residents to get out of town, especially those in mobile homes.

"If you can get out of Harrison County, get out of Harrison County," Spraggins said during an 8 a.m. Sunday briefing.

All shelters in Harrison County opened at noon Sunday. Spraggins said law enforcement officers will go to as many homes as possible asking those who refuse to evacuate to sign paperwork attesting to that effect.

He said casinos closed at 2 a.m. Sunday.

As guests leave, work crews board up the entrance of the Beau Rivage Hotel and Casino on Sunday as Hurricane Katrina bears down on the Gulf Coast. Drew Tarter/Sun Herald

Hancock County officials called for mandatory evacuations beginning at 6 a.m. for the entire county, including the cities of Bay St. Louis and Waveland.

In Pearl River County, Carolyn Nelson, coordinator of Emergency Management said at 9:30 a.m. that there were no mandatory evacuations and none were expected. The first shelter was to open in Picayune at 2 p.m., with others to be opened as needed.

"We're telling callers that if they have good sturdy homes and they not in a flood zone to stay," said Nelson, "Leaving is their call."

In Jackson County, mandatory evacuations were invoked at 8 a.m. Sunday for all areas south of U.S. 90 and in the Flood A zone and all low-lying areas. Darryl Goldmen, radio emergency community coordinator at county emergency management in Pascagoula, said all areas south of I-10 are "highly recommended" for evacuation.

"The people who have been calling haven't been giving me any lip," Goldmen said. "People are recognizing this is another Camille-type event and it has their attention."

In George County, Nancy Smith, administrative assistant to the director of emergency management, said shelters would open at 6 p.m. Sunday.

No mandatory evacuations had been ordered or in Stone County.