May 6, 2015

A Quick Update on the Low developing off the SE U.S. Coast

The system hasn't really developed much. Strong wind  shear aloft is causing the showers and storms to be displaced from the actually surface low center. This asymmetric structure to the clouds and showers being "removed"  from the actual is typical for subtropical systems.

This asymmetric structure to the clouds and showers being "removed"from the actual is typical for subtropical systems. (Where as a tropical system exhibits  more symmetry - clouds/showers are  concentric with respect to the low pressure center as is the wind field, too.) The guidance data is varying from one forecast cycle to another.

The latest tropical cyclone guidance is now leaning more toward a motion initially toward the north followed by a gradual turn northwest toward the SC/NC coastline. (map below)
TC Guidance
The ensemble data for the tropical models as well as from the GFS ensemble suite are also leaning toward a north track then bending back towards the SEUS coast.
TC Guidance Ensembles

GFS Ensembles (GEFS) for low off the SEUS Coast

Even more different is the actual GFS operational (OP) run that takes the low north then nearly due west to a landfall on the Georgia coast over the weekend. The movie loop below is the GFS "OP" run :

video

In general folks along the SEUS coast should continue to keep tabs on this system through the weekend. The system will bring gusty winds, heavy ran and rough surf with rip currents to the Carolina coasts south the Georgia and Florida, too over the next 3-4 days. And the system could strengthen into a weak subtropical or tropical storm with winds of perhaps 40-50 mph.