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Hurricane Elsa Discussion Number  28
NWS National Hurricane Center Miami FL       AL052021
1100 PM EDT Tue Jul 06 2021
 
After an earlier flurry of convective bursting and even the 
development of a eye in radar imagery, Elsa appears to have leveled 
off over the past couple of hours. Between 2100 UTC and 0000 UTC, 
WSR-88D radars from Tampa and Key West indicated areas of average 
Doppler velocities of 75-85 kt between 8000-13,000 ft, which were 
co-located with convective bands consisting of 50 dBZ and higher 
reflectivity values, which equates to at least 65 kt surface winds. 
Elsa's center also passed just barely to the east of Buoy 41023 
around 2100 UTC, producing a sustained wind of 49 kt at 3-meters 
elevation, which equals a 10-meter wind speed of 55 kt on the west 
side of the cyclone. The strongest 850-mb flight-level wind measured 
by an Air Force reconnaissance aircraft so far has been 74 kt. 
However, radar data indicate that the aircraft just missed the 
strongest winds in the convection by only about 5 n mi. The initial 
intensity is being held at 65 kt just in case convection redevelops 
around the ragged eye feature later tonight.

Elsa is moving northward, or 360/12 kt. This motion should continue 
tonight and early Wednesday until landfall occurs across the 
northwestern Florida peninsula. Thereafter, a gradual turn toward 
the north-northeast is expected by late Wednesday, followed by some 
acceleration toward the northeast on Thursday as Elsa rounds the 
western periphery of a deep-layer subtropical ridge and gets caught 
up by the southwesterly flow ahead of a mid-level trough. The 
official track forecast lies between the simple and 
corrected-consensus tracks models and the previous NHC track 
forecast.
 
Elsa's inner-core convection looks pretty ragged right now, but the 
vertical structure has improved based on the reconnaissance data, 
which indicate that the low-, middle- and upper-level circulations 
are nearly vertically stacked now. Elsa's ragged eye feature along 
with the very warm water beneath the cyclone and the upcoming 
nocturnal convective maximum period could combine to allow 
convection to redevelop. However, proximity to dry mid-level air 
just to the west should prevent any significant strengthening from 
occurring. After landfall, rapid weakening is expected due to 
increased frictional effects and Elsa's small size. The pressure 
gradient, however, is forecast by the GFS and ECMWF models to 
increase between Elsa and a sprawling surface high pressure system 
over the western Atlantic, which should act to increase the winds to 
tropical storm force near the coastal areas from Georgia to North 
Carolina on Wednesday and Thursday. The new NHC intensity forecast 
is similar to the previous advisory and follows the consensus 
intensity models HCCA and IVCN.
 
 
Key Messages:
 
1. Heavy rain will impact Cuba tonight resulting in significant 
flooding and mudslides. As Elsa moves across the western and 
northern Florida Peninsula through Wednesday, heavy rainfall may 
result in considerable flash, urban, and minor to isolated moderate 
river flooding.  Mid to late week, 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.
 
2. There is a danger of life-threatening storm surge along portions
of the west coast of Florida tonight and Wednesday, and a Storm
Surge Warning is in effect for that area.
 
3. Hurricane conditions are expected tonight and early Wednesday 
along a portion of the west coast of Florida, where a Hurricane 
Warning is in effect.  Tropical storm conditions are occurring 
across portions southwest Florida and will continue to spread 
northward along the west coast of the state within the warning area 
through Wednesday morning.
 
4. Although the center of Elsa is expected to remain inland of the
coastline from Georgia through the Carolinas during the next couple
of days, tropical storm conditions are expected along much of the
coasts of Georgia and South Carolina.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  07/0300Z 27.3N  83.2W   65 KT  75 MPH
 12H  07/1200Z 29.0N  83.1W   60 KT  70 MPH
 24H  08/0000Z 31.4N  82.5W   45 KT  50 MPH...INLAND
 36H  08/1200Z 33.9N  80.5W   35 KT  40 MPH...INLAND
 48H  09/0000Z 36.4N  77.4W   35 KT  40 MPH...INLAND
 60H  09/1200Z 39.3N  73.3W   40 KT  45 MPH...OVER WATER
 72H  10/0000Z 42.8N  68.0W   45 KT  50 MPH...OVER WATER
 96H  11/0000Z 51.0N  54.4W   45 KT  50 MPH...POST-TROP/EXTRATROP
120H  12/0000Z...DISSIPATED
 
$$
Forecaster Stewart
 
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