The National Weather Service has just upgraded the weather system in the northeastern Gulf of Mexico to Subtropical Depression Number 10.
It has issued a tropical storm warning from Apalachicola, Florida, west to the mouth of the Mississippi River - including New Orleans and Lake Pontchartrain.
That means the weather service expects tropical storm conditions within the next 24 hours.
At 10 a.m., Subtropical Depression 10 had a poorly defined center, about 45 miles southwest of Apalachicola, near latitude 29.2 north, longitude 85.5 west.
It was moving toward the northwest near 8 mph, and the weather service expects a turn to the west-northwest during the next 24 hours. If that happens, the center will be moving nearly parallel to the coastline today and tonight.
Maximum sustained winds are near 35 mph, with higher gusts. Some strengthening is forecast during the next 24 hours, and the depression could become a subtropical or tropical storm later today.
Mississippi coast residents should prepare for the likelihood of significant rains and wind by Friday night as a storm system advances in the Gulf of Mexico, the state's top emergency management official said Thursday.
"We are still planning as if this could be as bad as a Category 1 hurricane or more likely tropical force winds," said Mike Womack, director of the Mississippi Emergency Management Agency.
The National Weather Service said conditions are favorable for the system to become a subtropical or tropical cyclone before making landfall. Computer models show possible tracks across Alabama, Mississippi and Louisiana - areas still recovering from Hurricane Katrina.
Womack held conference calls with weather experts and coastal officials Thursday.
"I would say there is at least an 80 percent chance of significant rainfall and potential of tropical storm winds," Womack said.
He said the system remained very unpredictable but nothing above a Category 1 storm was expected. He noted that even a tropical storm could bring in flooding rains and wind damage.
Womack said emergency management directors in coastal Hancock, Harrison and Jackson counties were already in discussions about when to open shelters and order evacuations from flood-prone areas and Federal Emergency Management Agency trailers or other potentially unsturdy structures. He said if the situation remains as anticipated, the evacuation announcements could begin as early as noon Friday.
Residents should have a personal disaster kit and an evacuation plan in place. Those who live in coastal communities were taking notice, officials said, with increased numbers stocking up on supplies.
"We're taking precautionary plans to deal with anything from severe thunderstorms to a Category 1 coming close to our proximity," said Rupert Lacy, of the Harrison County Emergency Operations Center. "Hopefully we'll be prepared so if Mother Nature deems we are in a target area we'll be able to protect our citizens."
In Hancock County, emergency officials were handing out sandbags Thursday, said Brian Adam, director of the emergency management agency.
Adam said even though the low pressure system wasn't a named storm and its path wasn't certain, he wanted residents in low-lying areas to be prepared.
Gov. Haley Barbour said in a recorded telephone message that the system could affect Mississippi.
"Don't panic, but be prepared," Barbour said.
Automated calls with the governor's message started going out Wednesday night, primarily in parts of south Mississippi that were slammed by Hurricane Katrina on Aug. 29, 2005.
Lea Stokes, chief of staff for MEMA, said the automated calling system is part of a post-Katrina test project the Federal Emergency Management Agency has started in Mississippi, Louisiana and Alabama.
In the message, Barbour said people living in FEMA trailers should learn the location of the nearest storm shelter in case an evacuation is ordered.
Stokes said other concerns should the storm approach Mississippi and intensify were construction workers from other areas now on the coast as well as construction projects.
Emergency declared in Louisiana
Louisiana Gov. Kathleen Blanco declared a state of emergency late Thursday as an unpredictable weather disturbance in the Gulf of Mexico had potential to intensify and wreak havoc along the coast.
Mark Smith, a spokesman for the Office of Homeland Security and Emergency Preparedness, said the governor had ordered 100 school buses to be put on standby, along with ambulances and workers for emergency evacuation shelters. In addition, he noted, the declaration allows for the Louisiana National Guard to be put on alert as well.
"This thing is forecast currently to hit Louisiana and to be a tropical storm when it does," Smith said. "So, with Louisiana still suffering from the ravages of Katrina and having so many residents living in travel trailers and mobile homes, we feel it's prudent - at this time - less than 36 hours out from the onset of landfall, to recommend the governor make the declaration."