Official Discussion issued by the National Hurricane Center

Josephine (AL112020) DATA RELEASED: 8/13/2020 3:00:00 PM UTC

Copy of official data

Tropical Storm Josephine Discussion Number   8
NWS National Hurricane Center Miami FL       AL112020
1100 AM AST Thu Aug 13 2020

A just-received ASCAT overpass showed an area of 35-40 kt winds 
about 70 n mi north of the center of Tropical Depression Eleven, 
and based on this the cyclone is being upgraded to Tropical Storm 
Josephine with an initial intensity of 40 kt.  Satellite imagery 
shows that the convective pattern associated with Josephine has 
become a little better organized since the last advisory, with a 
ragged central convective feature and a weak band in the northern 
semicircle.

The initial motion is now west-northwestward or 295/13 kt.  
Josephine should continue this motion for the next several days as 
it moves toward a weakness in the western portion of the Atlantic 
subtropical ridge.  The global models forecast the western end of 
the ridge to weaken even more after 72-96 h, which should cause 
the cyclone, or what is left of it by that time, to turn 
northwestward.  The track guidance is tightly clustered, and the 
new forecast track lies a little to the right of the previous track 
and a little to the left of the consensus models.

Some additional strengthening appears likely during the next 24-  
36 h as Josephine moves through an environment of light vertical 
wind shear.  After that, the cyclone is expected to encounter 
moderate to strong southwesterly shear as it approaches an 
upper-level trough over the southwestern Atlantic, which should 
cause at least some weakening.  The new intensity forecast is 
adjusted upward for the first 72 h based on the current intensity.  
After 72 h, it shows weakening similar to the previous forecast, but 
not as drastic as the global models that show the storm degenerating 
to a tropical wave before 120 h.

Josephine is the earliest tenth tropical storm of record in the 
Atlantic, with the next earliest tenth storm being Tropical Storm 
Jose on August 22, 2005.


FORECAST POSITIONS AND MAX WINDS

INIT  13/1500Z 13.7N  49.2W   40 KT  45 MPH
12H  14/0000Z 14.5N  51.1W   45 KT  50 MPH
24H  14/1200Z 15.8N  53.6W   50 KT  60 MPH
36H  15/0000Z 17.1N  56.3W   50 KT  60 MPH
48H  15/1200Z 18.5N  58.9W   50 KT  60 MPH
60H  16/0000Z 19.9N  61.3W   45 KT  50 MPH
72H  16/1200Z 21.3N  63.6W   40 KT  45 MPH
96H  17/1200Z 24.0N  67.0W   30 KT  35 MPH
120H  18/1200Z 27.0N  68.0W   25 KT  30 MPH

$$
Forecaster Beven