Carolinas disturbance struggling with two centers

The area of disturbed weather (99L) moving towards the North Carolina/South Carolina coast is trying to get more organized, but has developed a split personality. With a west and an east circulation center just a few hundred miles apart (Figure 1), the two areas of disturbed weather are competing, and neither appears able to gain the upper hand. 99L cannot become a tropical depression until one center becomes dominant. As a result, the prospects for 99L making landfall as a strong tropical storm are growing increasingly dim, and it now appears that a 55-mph tropical storm will be the strongest system that will have time to form. The timing of landfall is problematic, since it is not clear which center will end up winning. Wind shear is higher over the western center (20 knots) than the eastern center (10 knots), so this may favor the eastern center winning out. The western center's thunderstorms should begin affecting the South Carolina/North Carolina coast Saturday night, and the the eastern center will begin affecting this region Sunday morning. Top winds found by the latest Hurricane Hunter aircraft around 7pm EDT were approximately 30 mph at the surface.


Figure 1. Satellite image of 99L showing the east and west centers competing to be boss. Whose side will the blob of thunderstorms in the middle choose?

I'll have a full analysis Saturday morning by 9:30am.

Jeff Masters