Official Discussion issued by the National Hurricane Center

Eleven (AL112020) DATA RELEASED: 8/12/2020 3:00:00 PM UTC

Copy of official data

Tropical Depression Eleven Discussion Number   4
NWS National Hurricane Center Miami FL       AL112020
1100 AM AST Wed Aug 12 2020

Satellite imagery indicates that the depression is a little better 
organized than 24 h ago, with a ragged central convective feature 
and a curved convective band in the northwestern semicircle.  
However, recent scatterometer data show this has not yet resulted 
in strengthening, with 25-30 kt winds occuring to the north of the 
center.  Based on the scatterometer, the initial intensity remains 
30 kt.

The initial motion remains a little north of due west, or
280/13 kt. There is little change to the forecast philosophy or 
the forecast track since the last advisory.  A westward motion is 
expected to continue through tonight 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, with that motion continuing through the end of 
the forecast period. The new NHC forecast is just to the left of 
the various consensus models.

The southeasterly shear that has so far prevented intensification 
should diminish in the next 12 h or so, which should allow the 
cyclone to become a tropical storm.  The system should then remain 
in light to moderate shear through about 48 h, and the intensity 
forecast calls for a peak intensity of 50 kt during that time.  
Later in the forecast period, moderate to strong southwesterly 
shear should develop over the cyclone due to an upper-level trough 
over the southwestern Atlantic.  This shear should cause the system 
to weaken, and several of the global models forecast it to 
degenerate to a tropical wave before 120 h.  The new intensity 
forecast will not call for that quick of a demise, but will show 
weakening due to the shear after 72 h.  The new forecast, which has 
only minor changes from the previous forecast, is near the upper 
edge of the intensity guidance.


INIT  12/1500Z 12.4N  44.2W   30 KT  35 MPH
12H  13/0000Z 12.8N  46.1W   35 KT  40 MPH
24H  13/1200Z 13.5N  48.4W   40 KT  45 MPH
36H  14/0000Z 14.5N  50.8W   45 KT  50 MPH
48H  14/1200Z 15.7N  53.3W   50 KT  60 MPH
60H  15/0000Z 17.0N  55.7W   50 KT  60 MPH
72H  15/1200Z 18.2N  58.1W   50 KT  60 MPH
96H  16/1200Z 20.5N  63.0W   40 KT  45 MPH
120H  17/1200Z 23.5N  66.5W   35 KT  40 MPH

Forecaster Beven