Official Discussion issued by the National Hurricane Center

Josephine (AL112020) DATA RELEASED: 8/15/2020 5:00:00 AM UTC

Copy of official data

Tropical Storm Josephine Discussion Number  15
NWS National Hurricane Center Miami FL       AL112020
500 AM AST Sat Aug 15 2020

Josephine continues to produce disorganized bursts of deep 
convection to the north and northeast of the estimated center, 
with little evidence of any banding features.  In spite of the 
shear, the storm is still producing high-level outflow into the 
strong upper-level winds.  The current intensity estimate of 40 kt 
is based on continuity from the previous scatterometer-based 
observations, and an ADT estimate from UW-CIMSS.  An Air Force 
Hurricane Hunter aircraft is scheduled to investigate the storm 
later this morning, and this should provide a good intensity 
estimate.  Since vertical shear associated with a large 
upper-level trough over the western Atlantic is forecast to become 
quite strong over the next few days, a weakening trend is likely to 
commence in a day or so.  The official forecast is similar to the 
previous NHC prediction.  It is also possible that the system will 
degenerate into an open wave within the next couple of days, as 
shown by the global models.

It is difficult to locate the center at this time, but it is 
believed to be situated near the southwest edge of the main area of 
deep  convection.  This leads to a somewhat uncertain initial 
motion estimate of 300/13 kt.  Josephine or its remnants are likely 
to continue to move west-northwestward to the south and southwest 
of a subtropical high pressure area, and then to turn northwest, 
north, and north-northeast along the periphery of the high.  The 
official track forecast remains close to the NOAA corrected model 
consensus prediction.


KEY MESSAGES:

1. Josephine should pass far enough to the northeast of the Leeward
Islands over the weekend to prevent major impacts.  However,
interests there should continue to monitor its progress until the
storm has passed north of that area.

2. Locally heavy rainfall is possible in the northern Leeward
Islands, the Virgin Islands, and Puerto Rico as Josephine passes by
to the northeast. Isolated minor flooding is possible in Puerto
Rico through Monday.


FORECAST POSITIONS AND MAX WINDS

INIT  15/0900Z 18.9N  58.4W   40 KT  45 MPH
12H  15/1800Z 19.6N  60.2W   40 KT  45 MPH
24H  16/0600Z 20.7N  62.5W   40 KT  45 MPH
36H  16/1800Z 22.0N  64.7W   35 KT  40 MPH
48H  17/0600Z 23.4N  66.7W   30 KT  35 MPH
60H  17/1800Z 24.9N  68.0W   30 KT  35 MPH
72H  18/0600Z 26.5N  68.5W   25 KT  30 MPH
96H  19/0600Z 29.0N  68.0W   25 KT  30 MPH...POST-TROP/REMNT LOW
120H  20/0600Z 33.0N  64.5W   20 KT  25 MPH...POST-TROP/REMNT LOW

$$
Forecaster Pasch