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Tropical Storm Elsa Discussion Number 21
NWS National Hurricane Center Miami FL AL052021
1100 AM EDT Mon Jul 05 2021
A NOAA Hurricane Hunter aircraft has been investigating Elsa while
it approaches the south coast of Cuba this morning. Based on
SFMR-observed surface winds from the aircraft, the intensity is held
at 55 kt for this advisory. A center dropsonde from the plane
measured 1009 mb with 26 kt at the surface, so the minimum central
pressure estimate is 1006 mb, indicating no significant change since
yesterday. Tail Doppler wind data from the NOAA plane showed that
there is an eastward tilt of the center with height, so the storm
continues to have some vertical alignment issues. Satellite imagery
continues to depict convective banding features over the eastern
portion of the circulation, with the center located near the western
edge of the main cloud mass.
Elsa continues its northwestward track with an initial motion
estimate of 310/12 kt. Over the next 2-3 days, the tropical
cyclone should move between a subtropical ridge over the southwest
North Atlantic and a mid-level low over the northern Gulf of
Mexico. In the latter part of the forecast period, Elsa is
forecast to accelerate northeastward into the westerlies off the
eastern United States coast and into the Atlantic, where it should
lose its tropical characteristics in the vicinity of Nova Scotia.
Over the eastern Gulf of Mexico, the official track track forecast
has been nudged slightly westward toward the model consensus aids,
HCCA and TVCA, but not as far west as that guidance. The GFS model
track lies a little east of the latest NHC track.
Some slight weakening is likely while Elsa crosses west-central Cuba
today. Restrengthening over the Gulf of Mexico is likely to be
limited by moderate westerly shear associated with a broad
upper-level trough over the Gulf. The official intensity forecast
is mostly higher than the numerical model consensus.
Key Messages:
1. Heavy rain will impact the Cayman Islands and Cuba today
resulting in significant flooding and mudslides over Cuba. As Elsa
approaches the Florida Keys, the Florida Peninsula, and coastal
Georgia through Wednesday, heavy rainfall may result in isolated
flash, urban, and minor river flooding. Mid to late week, heavy
rains across coastal South Carolina and North Carolina may result
in isolated flash and urban flooding.
2. Tropical storm conditions and a dangerous storm surge are
expected to continue across portions of central and western Cuba
today.
3. Tropical storm conditions are expected in portions of the
Florida Keys and along the Florida west coast tonight through
Tuesday night, where a Tropical Storm Warning is in effect. A
Tropical Storm Watch and a Storm Surge Watch are in effect for
portions of the west coast of Florida and the Florida Big Bend.
4. There is a risk of tropical storm conditions and storm surge
impacts along the coasts of Georgia and the Carolinas Wednesday and
Thursday.
FORECAST POSITIONS AND MAX WINDS
INIT 05/1500Z 21.5N 81.2W 55 KT 65 MPH
12H 06/0000Z 23.2N 82.2W 50 KT 60 MPH
24H 06/1200Z 25.0N 83.2W 55 KT 65 MPH
36H 07/0000Z 27.0N 83.6W 55 KT 65 MPH
48H 07/1200Z 29.3N 83.4W 55 KT 65 MPH
60H 08/0000Z 31.5N 82.2W 30 KT 35 MPH...INLAND
72H 08/1200Z 33.7N 79.8W 30 KT 35 MPH...INLAND
96H 09/1200Z 38.5N 72.5W 40 KT 45 MPH...OVER WATER
120H 10/1200Z 44.5N 61.5W 40 KT 45 MPH...POST-TROP/EXTRATROP
$$
Forecaster Pasch
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