Official Discussion issued by the National Hurricane Center

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

Copy of official data

Tropical Depression Eleven Discussion Number   2
NWS National Hurricane Center Miami FL       AL112020
1100 PM AST Tue Aug 11 2020

After weakening in the early evening hours, deep convection has 
returned to the western semicircle of the tropical cyclone.  While 
this is quite a strong burst, it appears that the convective 
pattern is indicative of the shear it is encountering, rather than 
any strengthening.  This is confirmed by ASCAT-B data from a few 
hours ago, which supported maintaining an initial wind speed of 30 
kt. 

By this time tomorrow, the depression is forecast to become a 
tropical storm due to decreasing vertical wind shear, and this 
environmental change should also keep some of the surrounding 
mid-level dry air from mixing near the center.  Gradually warming 
SSTs and relatively low shear conditions suggest further 
intensification through about 2-3 days.  Thereafter, increasing 
southwesterly shear while the small cyclone moves through fairly dry 
air aloft is forecast to cause a weakening trend, and it wouldn't 
be surprising if the cyclone even degenerates to a trough by day 5 
as it traverses the hostile environment.  The new NHC wind speed 
prediction is near but slightly higher than the previous advisory 
through 60h, similar afterwards, and lies near the NOAA 
corrected-consensus mean.  

The depression continues moving westward, or 280/12 kt, to the 
south of a large mid-tropospheric high centered over the central 
Atlantic. A break developing in the ridge should steer the 
depression more west-northwestward from 36 hours until the end of 
the forecast period. For a second advisory, the track models are in 
remarkably good agreement, and the forecast is near or northeast of 
the model consensus.  The HWRF solution that takes the cyclone near 
the Leeward Islands is considering less likely at this time, hence 
the official forecast is shaded toward the other model solutions.


FORECAST POSITIONS AND MAX WINDS

INIT  12/0300Z 12.0N  41.5W   30 KT  35 MPH
12H  12/1200Z 12.3N  43.4W   30 KT  35 MPH
24H  13/0000Z 12.8N  45.9W   35 KT  40 MPH
36H  13/1200Z 13.5N  48.3W   40 KT  45 MPH
48H  14/0000Z 14.5N  50.8W   45 KT  50 MPH
60H  14/1200Z 15.7N  53.3W   50 KT  60 MPH
72H  15/0000Z 17.0N  55.7W   45 KT  50 MPH
96H  16/0000Z 19.5N  60.5W   40 KT  45 MPH
120H  17/0000Z 22.0N  65.0W   35 KT  40 MPH

$$
Forecaster Blake