Tropical Storm Debby Discussion Number  21
NWS National Hurricane Center Miami FL       AL042024
1100 AM EDT Wed Aug 07 2024

Observations from an Air Force Hurricane Hunter aircraft indicate
surface winds to near 50 kt in an area located over 100 n mi
southeast of the center.  Most of Debby's deep convection is
occurring in bands well to the northeast and southeast of the
center, with limited shower and thunderstorm activity near/over the
center.  The advisory intensity is increased to 50 kt based on the
aircraft data.

The cyclone has been moving slowly northeastward and the initial
motion estimate is 040/4 kt.  Debby is currently situated between
two subtropical high pressure centers and remains within relatively
weak steering currents.  Later today and tonight, the ridge to
the east of Debby should build slightly and cause the system 
to move generally northward and make landfall in 12 to 24 hours.  
The steering flow ahead of a mid-latitude trough near the Great
Lakes is likely to cause Debby to accelerate north-northeastward to
northeastward over the eastern U.S. during the next few days.  The
NHC track forecast is similar to the previous one and is in good
agreement with the corrected consensus guidance.

Given that the strongest winds are occurring well to southeast of 
the center, Debby lacks a well-defined inner core, which indicates 
that significant re-intensification is not likely.  However, since 
the system lies over warm water this could allow for some  limited
strengthening before landfall and this is reflected in the official 
forecast.  The official forecast remains at the high end of the 
model intensity guidance.  Debby should merge with a frontal zone 
and become an extratropical cyclone over the northeastern U.S. in a 
couple of days.


Key Messages:

1. Heavy rainfall across portions of the Carolinas is expected to
persist through Thursday along with areas of considerable flooding.
Expected heavy rainfall will also result in considerable flooding
impacts across portions of the Mid-Atlantic States and Northeast
through Saturday morning.

2. Tropical storm conditions will affect portions of the South
Carolina and North Carolina coast through Thursday.  Tropical storm
warnings and watches are in effect for portions of that area.

3. Coastal flooding due to storm surge is likely along portions of
the South Carolina and North Carolina coastline through Thursday.


FORECAST POSITIONS AND MAX WINDS

INIT  07/1500Z 32.3N  79.2W   50 KT  60 MPH
12H  08/0000Z 32.9N  79.4W   55 KT  65 MPH
24H  08/1200Z 33.8N  79.7W   45 KT  50 MPH...INLAND
36H  09/0000Z 35.2N  79.9W   30 KT  35 MPH...INLAND
48H  09/1200Z 38.0N  79.1W   30 KT  35 MPH...INLAND
60H  10/0000Z 42.0N  76.0W   30 KT  35 MPH...POST-TROP/EXTRATROP
72H  10/1200Z 46.5N  71.0W   30 KT  35 MPH...POST-TROP/EXTRATROP
96H  11/1200Z 52.5N  60.0W   30 KT  35 MPH...POST-TROP/EXTRATROP
120H  12/1200Z 54.0N  52.0W   30 KT  35 MPH...POST-TROP/EXTRATROP

$$
Forecaster Pasch