As expected, the movement of TS Erika over Hispaniola along with vertical wind shear has caused Erika to weaken. Hurricane forecasters now expect that it may drop below tropical storm levels and become a tropical depression tomorrow. The circulation has tracked more to the west than the models were predicting, which has caused some changes in the predicted path.
The current path as of 8 pm shows a slow-moving tropical depression moving north through Florida Sunday through Tuesday and going into Georgia near Valdosta on Tuesday afternoon into Wednesday. This would likely cause significant flooding in some areas of south and central Georgia, bringing as much as 10 inches to some places IF IT HAPPENS. The bulk of the flooding would be likely to come mid- to late week.
It is important to keep in mind that the track forecasts are shifting each three hours as new data come in and Erika evolves. Early in the storm’s life, the predictions were for it to recurve to the northeast before it got to Florida. Now, a significant number of model paths put it into the Gulf of Mexico, while others bring it up the Florida panhandle. This uncertainty is likely to continue until Erika moves off of Hispaniola and back over the ocean. At that time forecasters will be able to see what is left of the circulation and make some judgments about the future development of the storm. The best you can do for the next day or two is to prepare for the worst (which will probably be the potential for heavy rain and flooding mid-week) and wait to see what really happens.
If you are interested in why predicting the strength of the storm is even harder than predicting the path, Dr. Marshall Shepherd of UGA has written a blog post for Forbes.com that addresses this topic.