Official Discussion issued by the National Hurricane Center

Joyce (AL102018) DATA RELEASED: 9/16/2018 11:00:00 AM UTC

Copy of official data

Tropical Depression Joyce Discussion Number  16
NWS National Hurricane Center Miami FL       AL102018
1100 AM AST Sun Sep 16 2018

Joyce is barely a tropical cyclone at the moment.  The cloud
pattern consists of a low-level swirl with a small patch of deep
convection located about 80 n mi northeast of the center and another
patch of weakening convection well removed from the center in the
northeast quadrant.  Visible satellite images and a partial ASCAT
pass indicate that the circulation of the cyclone has also become
increasingly elongated from northeast to southwest.  Based on the
system's appearance and the satellite intensity estimates, the
initial wind speed is lowered to 30 kt, making Joyce a tropical
depression.

The depression is moving east-northeastward at 16 kt within the
mid-latitude westerlies, and this motion should continue through
tonight.  After that time, the shallow cyclone is expected to slow
down and turn southeastward and then southwestward as it is moves
in the flow on the east side of a building low- to mid-level ridge.
The track models are in fairly good agreement, and little overall
change was made to the previous NHC forecast.

Joyce is currently in a quite hostile environment of 30-40 kt of
west-southwesterly shear.  Even though SSTs are relatively warm,
the ongoing strong shear and nearby dry air should continue to cause
the cyclone to gradually weaken.  Although the NHC forecast shows
Joyce hanging on as a tropical depression for a couple of more days,
it is very possible that the system could degenerate into a trough
or a remnant low at any time during that period.

FORECAST POSITIONS AND MAX WINDS

INIT  16/1500Z 34.7N  34.3W   30 KT  35 MPH
12H  17/0000Z 34.9N  31.4W   30 KT  35 MPH
24H  17/1200Z 34.5N  28.7W   30 KT  35 MPH
36H  18/0000Z 33.6N  27.0W   30 KT  35 MPH
48H  18/1200Z 32.6N  26.7W   25 KT  30 MPH
72H  19/1200Z 30.4N  29.2W   20 KT  25 MPH...POST-TROP/REMNT LOW
96H  20/1200Z...DISSIPATED

$$
Forecaster Cangialosi