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Tropical Storm Elsa Discussion Number  29
NWS National Hurricane Center Miami FL       AL052021
500 AM EDT Wed Jul 07 2021

The central convection associated with Elsa dissipated for a time 
earlier this morning, although the latest radar and satellite 
imagery shows a new band forming in the northern semicircle.  This 
decrease was likely caused by a combination of shear and dry air 
entrainment, and it has caused the cyclone to weaken.  Aircraft and 
surface observations indicate the central pressure has risen to 
near 1004 mb, and the initial intensity is decreased to a possibly 
generous 55 kt based on aircraft and Doppler radar data.

After a slight jog to the left, the storm has resumed a motion of 
360/12. This motion should continue for the next 12 h or so until 
landfall occurs across the northwestern Florida peninsula. 
Thereafter, a gradual turn toward the north-northeast is expected 
by, followed by acceleration toward the northeast as Elsa moves 
into the mid-latitude westerlies.  The forecast guidance has 
shifted a little to the left since the last advisory, and the new 
forecast track is also nudged in that direction.  The new track 
lies a little to the right of the various consensus models.

While little change in strength is forecast before landfall, there 
is a chance that the new convection could cause a short-lived 
re-intensification.  So, based on this possibility a hurricane 
warning remains in effect for portions of the west coast of 
Florida.  After landfall, Elsa should weaken as it crosses the 
southeastern United States, followed by some re-intensification as 
it accelerates back over the Atlantic.  The system is expected to 
become extratropical by the time it reaches the Canadian Maritimes 
in 72 h.  The new intensity forecast is at the upper edge of the 
guidance envelope and has only minor adjustments from the previous 
forecast.
 
 
Key Messages:
 
1. As Elsa moves across the western and northern Florida Peninsula 
today, heavy rainfall may result in considerable flash, urban, and 
isolated moderate river flooding.  Heavy rainfall across southeast 
Georgia, South Carolina, North Carolina, and southeastern Virginia 
may result in isolated flash and urban flooding, with considerable 
flash and urban flooding possible across coastal Georgia and the 
Lowcountry of South Carolina. Heavy rainfall across the Northeast 
and New England Thursday and Friday could lead to isolated flash and 
urban flooding.
 
2. There is a danger of life-threatening storm surge along portions
of the west coast of Florida today, and a Storm Surge Warning is in 
effect for that area.
 
3. Hurricane conditions are possible during the next several 
hours along a portion of the west coast of Florida, where a 
Hurricane Warning is in effect.  Tropical storm conditions are 
occurring across portions of the western Florida peninsula and will 
continue to spread northward along the west coast of the state 
within the warning area through today.
 
4. Although the center of Elsa is expected to remain inland of the
coastline from Georgia through the Carolinas during the next day 
or two, tropical storm conditions are expected along much of the
coasts of Georgia and South Carolina.  Tropical storm conditions 
are also possible along the coast of the mid-Atlantic state by 
Thursday night or Friday.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  07/0900Z 28.5N  83.5W   55 KT  65 MPH
 12H  07/1800Z 30.2N  83.3W   50 KT  60 MPH
 24H  08/0600Z 32.6N  82.0W   40 KT  45 MPH...INLAND
 36H  08/1800Z 35.3N  79.4W   35 KT  40 MPH...INLAND
 48H  09/0600Z 38.1N  75.6W   40 KT  45 MPH...INLAND
 60H  09/1800Z 41.5N  70.9W   45 KT  50 MPH...OVER WATER
 72H  10/0600Z 45.6N  64.6W   45 KT  50 MPH...POST-TROP/EXTRATROP
 96H  11/0600Z 54.0N  50.0W   45 KT  50 MPH...POST-TROP/EXTRATROP
120H  12/0600Z...DISSIPATED
 
$$
Forecaster Beven
 
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