373 
WTNT45 KNHC 140833
TCDAT5

Tropical Storm Joyce Discussion Number   7
NWS National Hurricane Center Miami FL       AL102018
500 AM AST Fri Sep 14 2018

There has been little change in the convective organization of
Joyce overnight.  The system continues to produce bands of
convection over the northeastern portion of the circulation, but
the center remains exposed due to shear.  The initial intensity is
held at 35 kt, in agreement with the earlier ASCAT data and recent
TAFB satellite estimate.

Joyce is still moving southwestward or 210 degrees at 7 kt.  Joyce
is being steered in that direction around the larger circulation of
Helene to its east-southeast.  Once Helene passes east-northeast of
Joyce later today, Joyce should turn eastward, then begin to
accelerate northeastward ahead of a mid-latitude trough over the
weekend.  The global models have trended toward a faster
northeastward motion after 24 h, and the NHC track forecast has been
adjusted in that direction as well.

Southwesterly upper-level winds are forecast to increase over the
cyclone within the next day or two, which should prevent Joyce from
strengthening.  The NHC forecast calls for little change in
wind speed over the next 36 h, then shows weakening as the shear
increases further. Both the GFS and ECMWF dissipate Joyce by day 4,
but the system could lose its deep convection and become
post-tropical before that time.

FORECAST POSITIONS AND MAX WINDS

INIT  14/0900Z 32.1N  44.9W   35 KT  40 MPH
 12H  14/1800Z 31.7N  44.7W   35 KT  40 MPH
 24H  15/0600Z 31.8N  43.7W   35 KT  40 MPH
 36H  15/1800Z 32.7N  42.5W   35 KT  40 MPH
 48H  16/0600Z 34.0N  40.7W   30 KT  35 MPH
 72H  17/0600Z 36.5N  34.5W   30 KT  35 MPH
 96H  18/0600Z...DISSIPATED

$$
Forecaster Brown