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Tropical Storm Elsa Discussion Number  18
NWS National Hurricane Center Miami FL       AL052021
500 PM EDT Sun Jul 04 2021
 
Elsa continues to exhibit some well-defined convective banding 
features over the northern and eastern portions of the circulation. 
Dvorak current intensity estimates from TAFB and SAB are 45 and 55 
kt respectively,so the advisory intensity remains at 50 kt.  
Although the cirrus-level outflow over the area looks fairly 
impressive, the SHIPS output diagnoses about 20 kt of vertical 
shear over the cyclone, which may be inhibiting strengthening.  
Another negative factor could be blockage of the low-level inflow 
by the land masses surrounding the cyclone.
 
The storm has turned toward the northwest, and the initial motion 
estimate is now 310/12 kt.  There is little change to the track 
forecast reasoning from the previous advisory package.  Elsa should 
move around the western periphery of a mid-level subtropical high 
pressure area during the next 3 days or so.  Thereafter, the 
system should accelerate northward to northeastward over 
the eastern United States and the northwest Atlantic.  No 
significant changes have been made to the NHC track forecast, which 
remains close to the simple and correct model consensus solutions.

Some strengthening could occur as the storm approaches the south 
coast of Cuba and although not explicitly shown in the official 
forecast, Elsa could strengthen to near 60 kt before landfall in 
that country.  Over the eastern Gulf of Mexico, southwesterly shear 
is expected to limit strengthening.  The official intensity 
forecast remains on the high side of the numerical model guidance.
 
 
Key Messages:
 
1. Widespread heavy rain will continue to affect portions of Jamaica 
tonight where isolated to scattered flash flooding and mudslides 
will be possible.  Heavy rain will then impact the Cayman Islands 
and Cuba through Monday resulting in significant flooding and 
mudslides over Cuba.  As Elsa approaches the Florida Keys, Florida 
Peninsula, and coastal Georgia Monday through Wednesday, heavy 
rainfall may result in isolated flash, urban, and minor river 
flooding.
 
2. Tropical storm conditions and a dangerous storm surge are 
expected with hurricane conditions possible in portions of eastern 
Cuba tonight.  Tropical storm conditions are expected in portions 
of central and western Cuba tonight and Monday, and will spread 
into portions of the Florida Keys by late Monday. 
 
3. Tropical Storm and Surge Surge Watches are in effect for  
portions of the west coast of the Florida peninsula where tropical 
storm conditions and a dangerous storm surge are possible beginning 
as early as Monday night and continuing into Tuesday. 

4. There is a risk of tropical storm conditions, storm surge,
and rainfall impacts along the remainder of the Florida Peninsula
Tuesday night through Wednesday and the coasts of Georgia and the
Carolinas Wednesday and Thursday. 
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  04/2100Z 19.8N  77.9W   50 KT  60 MPH
 12H  05/0600Z 21.1N  79.4W   55 KT  65 MPH
 24H  05/1800Z 22.7N  81.2W   50 KT  60 MPH...INLAND
 36H  06/0600Z 24.2N  82.4W   50 KT  60 MPH...OVER WATER
 48H  06/1800Z 25.8N  83.0W   50 KT  60 MPH
 60H  07/0600Z 27.9N  83.0W   50 KT  60 MPH
 72H  07/1800Z 30.5N  82.3W   30 KT  35 MPH...INLAND
 96H  08/1800Z 34.9N  78.0W   30 KT  35 MPH...INLAND
120H  09/1800Z 40.0N  69.0W   35 KT  40 MPH...OVER WATER
 
$$
Forecaster Pasch
 
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