Official Discussion issued by the National Hurricane Center

Eleven (AL112020) DATA RELEASED: 8/12/2020 9:00:00 PM UTC

Copy of official data

Tropical Depression Eleven Discussion Number   5
NWS National Hurricane Center Miami FL       AL112020
500 PM AST Wed Aug 12 2020

Satellite imagery this afternoon shows some changes in the 
convection associated with Tropical Depression Eleven, as the 
showers and thunderstorms are now occuring more in curved bands and 
less in sheared bursts.  This is likely due to the southeasterly 
shear which has been affecting the depression finally letting up.  
However, this change has not caused the satellite intensity 
estimates to change significantly since the last advisory, so the 
initial intensity is again 30 kt.

The initial motion remains a little north of due west, or
280/13 kt. There is almost no change to the forecast philosophy and 
little change to the forecast track since the last advisory.  A 
westward motion is expected to continue for another 6-12 h due to 
easterly flow on the south side of a strong subtropical ridge 
situated to the north of the cyclone.  After that, the global 
models forecast a slight weakness to develop within the ridge, 
allowing the cyclone to turn west-northwestward and continue that 
motion through 96 h.  Between 96-120 h, the western end of the 
ridge is forecast to weaken more, which should cause a turn toward 
the northwest.  The new NHC forecast track remains just to the left 
of the various consensus models.

The cyclone should be in an environment of light to moderate shear 
through the next 48 h or so.  The intensity forecast again calls 
for a peak intensity of 50 kt during this time, which is at the 
high end of the intensity guidance.  After 60 h, the cyclone is 
expected to encounter moderate to strong southwesterly shear 
associated with a large upper-level trough over the southwestern 
Atlantic.  This should cause at least steady weakening, and several 
of the global models continue to forecast the cyclone to degenerate 
to a tropical wave before 120 h.  The new intensity forecast again 
expects the system to last longer than the global models, but still 
shows weakening due to the shear after 72 h.  The new forecast has 
only minor changes from the previous forecast.


FORECAST POSITIONS AND MAX WINDS

INIT  12/2100Z 12.7N  45.7W   30 KT  35 MPH
12H  13/0600Z 13.0N  47.5W   35 KT  40 MPH
24H  13/1800Z 14.0N  49.9W   40 KT  45 MPH
36H  14/0600Z 15.2N  52.2W   45 KT  50 MPH
48H  14/1800Z 16.6N  54.8W   50 KT  60 MPH
60H  15/0600Z 17.8N  57.3W   50 KT  60 MPH
72H  15/1800Z 19.1N  59.7W   50 KT  60 MPH
96H  16/1800Z 21.5N  64.5W   40 KT  45 MPH
120H  17/1800Z 24.5N  67.0W   30 KT  35 MPH

$$
Forecaster Beven