Issued at 1100 AM EDT Sun Jul 04 2021


000
WTNT45 KNHC 041457
TCDAT5
 
Tropical Storm Elsa Discussion Number  17
NWS National Hurricane Center Miami FL       AL052021
1100 AM EDT Sun Jul 04 2021
 
A NOAA P-3 Hurricane Hunter aircraft has been investigating Elsa
this morning.  Flight-level and SFMR surface observations from
the aircraft indicate that the maximum winds are near 50 kt and the
estimated central pressure, about 1009 mb, is rather high for a 
system of this intensity.  Also, tail Doppler radar data from the 
aircraft show an eastward tilt of the center with height.  
Nonetheless, the storm still looks fairly impressive on satellite 
images with a well-defined convective banding feature over the 
northern through eastern portions of the circulation.  Also, the 
highest cloud tops are quite cold and near -70C.
 
Elsa's forward speed has slowed a little more, and the current 
motion is around 290/11 kt.  There hasn't been much change to the 
track forecast or reasoning since the previous advisory.  Over 
the next few days, the tropical cyclone should move around the 
western periphery of the subtropical ridge.  The NHC forecast track 
is similar to the previous official forecast, and close to the 
model consensus.  The latest GFS and HWRF solutions are to the west 
of this forecast.

Elsa should remain in a low-shear environment through Monday, and 
some strengthening is likely before the storm reaches Cuba, 
assuming the circulation becomes better aligned vertically.  The 
storm should weaken somewhat due to its passage over Cuba.  After 
the cyclone emerges into the southeastern Gulf of Mexico, only 
slight restrengthening is forecast due to moderate southwesterly 
shear.  The official intensity forecast is on the high end of the 
numerical intensity guidance suite.


Key Messages:
 
1. Widespread heavy rain will continue to affect portions of 
southern Haiti and Jamaica today where isolated to scattered flash 
flooding and mudslides will be possible. Heavy rain will then impact 
the Cayman Islands and Cuba today into Monday resulting in 
significant flooding and mudslides over Cuba. As Elsa approaches the 
Florida Keys and Florida Peninsula Monday through Wednesday, heavy 
rainfall may result in isolated flash, urban, and minor river 
flooding.
 
2. Tropical storm conditions and dangerous storm surge are expected
with hurricane conditions possible in portions of eastern Cuba later 
today and tonight.  Tropical storm conditions are expected in 
portions of central and western Cuba tonight and Monday.
 
3. Tropical storm conditions, storm surge, and rainfall impacts are
expected beginning late Monday in the Florida Keys, and are 
possible along the coast of southwestern Florida beginning 
Monday night.  Tropical Storm Warnings and Watches are in 
effect in those areas. 
 
4. There is a risk of tropical storm conditions, storm surge,
and rainfall impacts along the remainder of the Florida Peninsula 
Monday night through Wednesday and the coasts of Georgia and the 
Carolinas Wednesday and Thursday.  However, uncertainty in the 
forecast remains larger than usual due to Elsa's potential 
interaction with Cuba.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  04/1500Z 18.7N  76.8W   50 KT  60 MPH
 12H  05/0000Z 20.2N  78.2W   55 KT  65 MPH
 24H  05/1200Z 21.9N  80.0W   60 KT  70 MPH...INLAND
 36H  06/0000Z 23.4N  81.5W   50 KT  60 MPH...OVER WATER
 48H  06/1200Z 24.7N  82.5W   50 KT  60 MPH
 60H  07/0000Z 26.5N  83.0W   50 KT  60 MPH
 72H  07/1200Z 28.6N  82.8W   50 KT  60 MPH
 96H  08/1200Z 33.5N  79.5W   40 KT  45 MPH...INLAND
120H  09/1200Z 38.5N  71.0W   35 KT  40 MPH...OVER WATER
 
$$
Forecaster Pasch