Areas from the western Florida Panhandle to the Texas coast are at risk at this early stage for such an occurrence.

Other issues to consider with the long-duration, meandering tropical system include potential for long-duration storm surge.

Meteorologist Mark Mancuso can see how New Orleans, with its levee system in question, could be hit with over a foot of rain, a challenge within itself. "It's not just the rainfall, but perhaps days of pressure on levees, as storm surge water could be driven into Lake Pontchartrain if a tropical storm or hurricane hangs out over the north-central Gulf of Mexico," Mancuso said.

The relentless circulation around a slow-moving tropical storm or hurricane can greatly raise water levels on shorelines and bays to its north and east. Other areas are vulnerable as well.

Hurricane Ike, which moved steadily along, was preceded by a flooding storm surge well in advance on the northwestern Gulf coast.

The developing tropical system in the Gulf can move just about anywhere. That movement includes zigzags, loops, a 180-degree change in direction, a stall, and perhaps a slow, steady straight path inland.

Considering potential for damage, impact to the petroleum industry and commerce in the Gulf Coast region, the system, as of yet to gather a name, could be the next billion-dollar disaster in a mountainous year of costly storms for the U.S.

The FEMA budget is already in trouble.

The latest consensus is that little or no rain from the system will reach very far into the neediest areas of Texas and Oklahoma.

However, at least the system will help to pull cooler air down into Oklahoma and the Lone Star State from north to south over the Labor Day weekend, ending the agonizing nearly summer-long heat wave.