Big Labor Day Rainfall, Flooding in part of the Southeast

Developing tropical storm "Lee" is going to steal the show over the next few days and into next week. All the models agree on pulling the system slowly northward into Louisiana and  then it lolligags and interacts with a frong over the Tennessee Valley and Southeast.  The 3 main camps for the track are 1) the storm gets missed, and just stalls in southern Louisiana  2), the storm gets fully swept up by the front Sunday and gets sheared up the east coast and 3), the front acts to pull it inland, then leaves part of the circulation behind and awaits the next front later next week.  The third option is what the GFS and ECMWF models are going for right now and thats how I'm leaning, but its not certain at this early stage yet. The guaranteed heavy rains are in southern Louisiana and the Gulf coast of Miss, Alabama. Where over 10" and possibly up to 20" of rain will fall.

The unusual aspect of this storm is how it may interact with a decaying front, allowing a slow moving, long duration heavy rain event to unfold. Usually, the first part of the heavy rains occur on the western flank of the circulation, and where the front enhances convergence, and that means Sunday and Mondays heavy rains will occur in Louisiana, spreading into southeast Arkansas , western Tennessee and northern Mississippi and Alabama...but by later Monday that heavy rain will transfer quickly eastward to the front as its draped from central Tennessee , northern half of Alabama and northern GA and western Carolinas.  If the front moves as slow as shown by the GFS and ECMWF, and the tropical depression remains in Alabama, that would place the mountains of Georgia and western NC in a true flood event, with possibly a foot of rain falling in a couple of days.  But its still early and the models are just now latching on to the track of the system and how it interacts. Overall, an unusual setup.  Normally, a tropical system comes inland and moves right along, but those few that don't, (like Alberto for example), extreme rain amounts can occur.

Heavy Rain potential Sunday through Most of next week.