Tropical Storm Chantal formed more or less on schedule from the old front draped from North Florida across the warm Gulf Stream waters offshore of Georgia and the Carolinas. The atmospheric pattern is only marginal over the system, so dramatic intensification is not expected before landfall during the first half of tomorrow (Sunday).
The steering is courtesy of the upper-level disturbance that was sitting over Florida enhancing the rainfall. That system has now moved into the Gulf. The circulation around the right side of the disturbance is from the south, so that will push Chantal and the attached band of deep tropical moisture toward the Carolina coast.
There is high confidence in the forecast track and that very heavy rain will fall in the tropical moisture bands. The system is not symmetric, however, because the upper-level winds are tilting it toward the east, so the heaviest rain will fall to the right of where Chantal’s center makes landfall. The focus looks likely to be from the Myrtle Beach, SC area through eastern North Carolina. The National Weather Service is predicting 2-4 inches of rain with Chantal, with some spots getting more…