Issued at 500 PM EDT Sun Aug 04 2024
000
WTNT44 KNHC 042052
TCDAT4
Tropical Storm Debby Discussion Number 10
NWS National Hurricane Center Miami FL AL042024
500 PM EDT Sun Aug 04 2024
Debby's cloud pattern continues to show increasing organization on
satellite images although there is limited deep convection over the
southwest quadrant of the circulation. The upper-level
anticyclonic outflow pattern is well-defined. The latest Air Force
Hurricane Hunter aircraft observations indicated that the central
pressure hadn't changed much and the wind data from the aircraft
continued to support an intensity of near 55 kt. WSR-88D radar
imagery shows that an eyewall may be trying to close off, and
another Hurricane Hunter aircraft will be investigating Debby in a
few hours to assess the strength of the cyclone.
The cyclone has turned toward the north and is now moving at around
360/10 kt. Debby should continue to move through a break in the
subtropical ridge due to a trough over the eastern United States
for the next day or so, and this motion should bring the center of
the system to the northeast Gulf of Mexico coast around midday
tomorrow. Thereafter, the trough moves eastward, leaving Debby in
weak steering currents for a few days. The track guidance shows
decreasing forward speed and a turn to the east in 24-48 hours.
Some of the track models show the cyclone moving temporarily over
the Atlantic in the 72-hour time frame, and so does the official
forecast.
Debby will continue to move over waters of high heat content
and remain in an environment of low vertical wind shear into Monday
morning. Some dry air intrusion over the southwestern portion of
the circulation may have temporarily interrupted the intensification
process. However, given the favorable oceanic and shear
conditions, significant strengthening is expected before landfall.
Rapid intensification is especially likely if Debby acquires a
well-defined inner core. The official intensity forecast is at the
high end of the model guidance. Although weakening will occur
after landfall, the longer-term strength of the system is
largely dependent on how long it remains over land. Currently the
official forecast shows some re-intensification with Debby moving
into the Atlantic, but how much the system will restrengthen is
highly uncertain.
Key Messages:
1. Potentially historic heavy rainfall across southeast Georgia and
South Carolina through Friday morning will likely result in areas of
catastrophic flooding. Heavy rainfall will likely result in
considerable flooding impacts from the Florida Big Bend region
through southeast GA and the Coastal Plain of the Carolinas through
Friday.
2. There is a danger of life-threatening storm surge along portions
of the Gulf Coast of Florida, with 6 to 10 feet of inundation above
ground level expected somewhere between Ochlockonee River and
Suwannee River on Monday. Residents in the Storm Surge Warning area
should follow any advice given by local officials.
3. Hurricane conditions are expected Monday along portions of the
Florida Big Bend region where a Hurricane Warning is in effect, with
tropical storm conditions beginning this evening. Tropical storm
conditions are expected through Monday farther south within the
Tropical Storm Warning along Florida's west coast, including the
Tampa Bay area.
4. Dangerous storm surge and wind impacts are expected along
portions of the southeast U.S. coast from northeastern Florida to
North Carolina through the middle of the week, and storm surge
warnings and tropical storm watches and warnings have been issued
for portions of these areas.
FORECAST POSITIONS AND MAX WINDS
INIT 04/2100Z 27.7N 84.4W 55 KT 65 MPH
12H 05/0600Z 29.1N 84.4W 75 KT 85 MPH
24H 05/1800Z 30.5N 83.8W 75 KT 85 MPH...INLAND
36H 06/0600Z 31.3N 83.0W 45 KT 50 MPH...INLAND
48H 06/1800Z 31.7N 82.1W 35 KT 40 MPH...INLAND
60H 07/0600Z 31.7N 81.1W 40 KT 45 MPH...INLAND
72H 07/1800Z 31.9N 80.5W 45 KT 50 MPH...OVER WATER
96H 08/1800Z 32.6N 80.1W 45 KT 50 MPH...INLAND
120H 09/1800Z 34.0N 79.5W 30 KT 35 MPH...INLAND
$$
Forecaster Pasch
More...
000
WTNT44 KNHC 042052
TCDAT4
Tropical Storm Debby Discussion Number 10
NWS National Hurricane Center Miami FL AL042024
500 PM EDT Sun Aug 04 2024
Debby's cloud pattern continues to show increasing organization on
satellite images although there is limited deep convection over the
southwest quadrant of the circulation. The upper-level
anticyclonic outflow pattern is well-defined. The latest Air Force
Hurricane Hunter aircraft observations indicated that the central
pressure hadn't changed much and the wind data from the aircraft
continued to support an intensity of near 55 kt. WSR-88D radar
imagery shows that an eyewall may be trying to close off, and
another Hurricane Hunter aircraft will be investigating Debby in a
few hours to assess the strength of the cyclone.
The cyclone has turned toward the north and is now moving at around
360/10 kt. Debby should continue to move through a break in the
subtropical ridge due to a trough over the eastern United States
for the next day or so, and this motion should bring the center of
the system to the northeast Gulf of Mexico coast around midday
tomorrow. Thereafter, the trough moves eastward, leaving Debby in
weak steering currents for a few days. The track guidance shows
decreasing forward speed and a turn to the east in 24-48 hours.
Some of the track models show the cyclone moving temporarily over
the Atlantic in the 72-hour time frame, and so does the official
forecast.
Debby will continue to move over waters of high heat content
and remain in an environment of low vertical wind shear into Monday
morning. Some dry air intrusion over the southwestern portion of
the circulation may have temporarily interrupted the intensification
process. However, given the favorable oceanic and shear
conditions, significant strengthening is expected before landfall.
Rapid intensification is especially likely if Debby acquires a
well-defined inner core. The official intensity forecast is at the
high end of the model guidance. Although weakening will occur
after landfall, the longer-term strength of the system is
largely dependent on how long it remains over land. Currently the
official forecast shows some re-intensification with Debby moving
into the Atlantic, but how much the system will restrengthen is
highly uncertain.
Key Messages:
1. Potentially historic heavy rainfall across southeast Georgia and
South Carolina through Friday morning will likely result in areas of
catastrophic flooding. Heavy rainfall will likely result in
considerable flooding impacts from the Florida Big Bend region
through southeast GA and the Coastal Plain of the Carolinas through
Friday.
2. There is a danger of life-threatening storm surge along portions
of the Gulf Coast of Florida, with 6 to 10 feet of inundation above
ground level expected somewhere between Ochlockonee River and
Suwannee River on Monday. Residents in the Storm Surge Warning area
should follow any advice given by local officials.
3. Hurricane conditions are expected Monday along portions of the
Florida Big Bend region where a Hurricane Warning is in effect, with
tropical storm conditions beginning this evening. Tropical storm
conditions are expected through Monday farther south within the
Tropical Storm Warning along Florida's west coast, including the
Tampa Bay area.
4. Dangerous storm surge and wind impacts are expected along
portions of the southeast U.S. coast from northeastern Florida to
North Carolina through the middle of the week, and storm surge
warnings and tropical storm watches and warnings have been issued
for portions of these areas.
FORECAST POSITIONS AND MAX WINDS
INIT 04/2100Z 27.7N 84.4W 55 KT 65 MPH
12H 05/0600Z 29.1N 84.4W 75 KT 85 MPH
24H 05/1800Z 30.5N 83.8W 75 KT 85 MPH...INLAND
36H 06/0600Z 31.3N 83.0W 45 KT 50 MPH...INLAND
48H 06/1800Z 31.7N 82.1W 35 KT 40 MPH...INLAND
60H 07/0600Z 31.7N 81.1W 40 KT 45 MPH...INLAND
72H 07/1800Z 31.9N 80.5W 45 KT 50 MPH...OVER WATER
96H 08/1800Z 32.6N 80.1W 45 KT 50 MPH...INLAND
120H 09/1800Z 34.0N 79.5W 30 KT 35 MPH...INLAND
$$
Forecaster Pasch
More...