Sept 24, 2024 Tropical Storm Helene Forecast to Rapidly Intensify

Helene likely to landfall as a major hurricane along Florida panhandle coast

• Major Hurricane Helene forecast to landfall Florida panhandle coast on Thursday

• Mesoscale Model Solutions are with Category 5 pressures, insane

• Inland wind and flooding threat into Georgia and South Carolina into Friday potentially affecting Atlanta

• Atlantic tropics remain active for the next 2-weeks into early October.

• Hurricane John comes back around

The low-level circulation of Helene is exposed to the southwest as wind shear continues to hold back the development process. However, that heavy band of convection isn’t going away.

NHC 11 AM Advisory | Very Large Helene

Helene's forecast radii are at the 90th percentile of hurricane size at similar latitudes.  Due to the forecast large size of this system, storm surge, wind, and rainfall impacts will extend well away from the center, particularly on the east side.  In addition, the fast forward speed while it crosses the coast will likely result in farther inland penetration of strong winds over parts of the southeastern United States after landfall.

The (near) landfall intensity is still Major (M) at 100-knots but could be higher, unfortunately into the Florida Gulf Coast just south of Tallahassee into Wakulla County. Storm surge along the west coast of Florida into the Big Bend will be unbelievable and damaging a la Dennis (2004).

Interesting that the track forecast is west of the 06z models including GFS and DWD ICON favoring more so the ECMWF 06z. I would not be surprised to see an eastward shift in the guidance, but the lack of low-level circulation until recently (or perhaps it is gone again) means we can’t solidify the track quite yet.

GFS, ECMWF, ICON 06z

NHC Intensity Discussion

Update on intensity from NHC shows 100-knots in 48-hours — that’s from TS to Major in very rapid intensification burst. I would take the over on this intensity forecast, unfortunately, based upon the guidance.