Tropical Storm Debby Discussion Number  17
NWS National Hurricane Center Miami FL       AL042024
1100 AM EDT Tue Aug 06 2024

Surface synoptic data, satellite imagery, and WSR-88D radar 
observations indicate that the center of the cyclone is near 
the coastline in the vicinity of the Georgia/South Carolina border.  
As a result of its interaction with land, Debby's intensity has 
decreased to near 35 kt.  Most of the deep convection is occurring 
in bands well to the east and northeast of the center as drier air 
has been impinging on the southwestern quadrant of the circulation.

Debby has been gradually turning to the right and slowing down, 
with a current motion estimate of around 060/5 kt.  The cyclone is 
situated in an area of weak steering currents within the subtropical 
ridge.  The track guidance shows a slow, generally eastward motion 
during the next day or so, bringing the center out over the South 
Carolina coastal waters.  By late tomorrow and early Thursday, the 
global models predict a strengthening mid-level ridge to the east of 
Debby.  This evolution should cause the system to turn northward 
and north-northwestward and move back over the coastline in 36 to 
48 hours.  Thereafter, Debby is expected to move northeastward near
the northeast U.S. coast at an increasing forward speed, ahead of a
mid-tropospheric trough moving into the Ohio Valley region.  The
official forecast is a blend of the latest model consensus 
predictions.

Although the center of Debby is forecast to be over water later 
today, the lack of an inner core should allow only slow 
re-strengthening for the next day or so.  Since the system is not 
expected to move far enough offshore to interact significantly with 
the Gulf Stream, this should limit the amount of oceanic heat 
content available to the storm.  The official intensity forecast 
is near or slightly above the latest statistical/dynamical DSHIPS 
and LGEM guidance.


Key Messages:

1.Potentially historic heavy rainfall across eastern South Carolina 
through Friday will likely result in areas of catastrophic flooding. 
Heavy rainfall will likely result in flooding impacts from northern 
North Carolina through portions of Mid-Atlantic States and southern 
New England through Sunday morning. 

2. Dangerous storm surge and tropical storm conditions will spread
northward along the southeast U.S. coast from northeastern Georgia 
to North Carolina through Thursday. Storm surge and tropical storm 
watches and warnings are in effect for portions of these areas. 
Residents in the storm surge watch and warning area should follow 
any advice given by local officials.

3. In portions of Florida where Debby has passed, deadly hazards
remain, including downed power lines and flooded areas. Ensure
generators are properly ventilated to avoid carbon monoxide
poisoning.  Exercise caution when using chainsaws and power tools,
and drink plenty of water to avoid heat exhaustion.


FORECAST POSITIONS AND MAX WINDS

INIT  06/1500Z 31.9N  81.0W   35 KT  40 MPH
12H  07/0000Z 32.0N  80.2W   40 KT  45 MPH
24H  07/1200Z 32.2N  79.4W   45 KT  50 MPH
36H  08/0000Z 32.6N  79.3W   50 KT  60 MPH
48H  08/1200Z 33.2N  79.6W   50 KT  60 MPH...INLAND
60H  09/0000Z 34.2N  79.9W   40 KT  45 MPH...INLAND
72H  09/1200Z 35.7N  79.6W   35 KT  40 MPH...INLAND
96H  10/1200Z 40.2N  75.3W   30 KT  35 MPH...POST-TROPICAL
120H  11/1200Z 45.0N  69.0W   30 KT  35 MPH...POST-TROP/EXTRATROP

$$
Forecaster Pasch