*******Note that forecast and outlooks in this post are NOT the official forecast from the National Hurricane Center (NHC). They are my own detailed views on the Atlantic tropics based on current observations and latest computer model runs. As such do not make decisions based on my posts...consult news media...watches and warnings from your local weather office...and any evacuation orders issued by local governments to make the most informed and best decisions. Visit the NHC website hurricanes.gov (hurricanes dot gov) for the latest watches/warnings and official forecasts on active tropical cyclones.*********
...SATURDAY AUGUST 3 2024 11:50 PM EDT...
Satellite image of newly-formed Tropical Storm Debby centered in the southeastern Gulf of Mexico as of 2110Z:
While crossing Cuba and turning north into the southeastern Gulf of Mexico… the organizing tropical wave of low pressure previously tagged potential tropical cyclone four developed a well-defined surface center early Saturday and was upgraded to tropical depression four. By 5 PM EDT ship observations… surface observations in the Florida Keys… and a satellite scan of winds indicated the depression has strengthened into Tropical Storm Debby with 40 mph maximum sustained winds. As of 11 PM EDT Debby has strengthened further to 45 mph maximum sustained winds per aircraft recon measurements. This special update is to highlight notable changes in the short-term and long-term forecast for Debby.
Short-term forecast changes… the well-defined surface center ended up taking shape further south on the south coast of Cuba instead of the north coast. As a result what is now Debby is taking a wider turn around the west side of the Atlantic surface ridge and across eastern Gulf of Mexico that will be further away from the Florida peninsula. The increased time over the rather warm 30+ deg C water… combined with good upper air ventilation beneath the overhead upper anticyclone and possible northern outflow enhancement induced southerly upper flow ahead of the approaching eastern North America upper trough… means Debby is now expected to briskly intensify into a hurricane in the next 24 hours before landfall with the northwest Florida peninsula coast or far eastern Florida panhandle coast. For now the only piece of good news is Debby has not yet developed a well-defined thunderstorm core on nighttime infrared satellite pictures such that intensity above category 1 is not expected at this time for the northern Florida landfall… however should a thunderstorm core develop in the overnight then category 2 cannot be ruled out for the landfall intensity:
(1) The Florida Keys are currently being buffeted by tropical storm conditions (heavy rain… gusty winds… and coastal surf) as the center of Debby is now passing by to the west… a gust of 48 mph was recently measured at the National Weather Service station at Key West (weather.gov). Storm force conditions should relax later today as the storm center continues north and away.
(2) The southeastern and east-central parts of the Florida peninsula will not see storm force conditions… however bands of heavy rainfall with flash flood potential will overspend the region in the next 24 hours.
(3) The western half of the Florida peninsula will see gusty winds with isolated damage potential and coastal surf in addition to the heavy rains bands in the next 24 hours. Interests across the northern-third of the Florida peninsula… southeastern Georgia… and far eastern Panhandle should now be adapting to the recent short-term forecast changes by rushing preparations to completion by Sunday late afternoon for the following: heavy rains with flash flood potential… potential for widespread damage from coastal storm surge and hurricane-force winds to arrive on the northwest Florida peninsula coast or far eastern Florida panhandle coast… with strong winds with damage potential spreading inland across the northern-third of the peninsula… far eastern panhandle… and southeastern Georgia through Monday. Coastal Georgia and northeastern Florida will see an increase in coastal surf as the center of Debby is bent northeast toward the Atlantic while pulled by the current eastern North America upper trough.
Long-term forecast changes… models have come into agreement that the current eastern North America upper trough will leave behind a vortex… with the east side of the vortex hooking Debby northward into both coastal and inland areas of the Carolinas after Monday. Interests across the Carolinas (both coastal and inland) should now be monitoring Debby and be ready to start preparations as early as tomorrow evening as the specifics of the longer-range fate of Debby become clearer.
My weekend full update on the Atlantic tropics is due early Sunday… which will have more information on Debby and the rest of the Atlantic tropics.
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