385 
WTNT45 KNHC 180252
TCDAT5

Tropical Depression Ten Discussion Number   3
NWS National Hurricane Center Miami FL       AL102019
1100 PM AST Tue Sep 17 2019

Convection associated with Tropical Depression Ten has increased
and become better organized since the last advisory, and various
subjective and objective satellite intensity estimates are now in
the 35-40 kt range.  However, just-received ASCAT-C data indicates
that, despite this increase in organization, the surface winds have
not yet reached 35 kt.  Based on this, the cyclone remains a 30 kt
depression for this advisory.

The initial motion is now 285/9.  The cyclone is to the south of a
low- to mid-level ridge, and this feature should steer the system
generally west-northwestward with an increase in forward speed
during the next 3-4 days.  Near the end of the forecast period, the
cyclone should approach a weakness in the ridge and turn more
northwestward.  The track guidance is in generally good agreement
with this scenario, with the GFS near the northern edge of the
guidance and the HWRF remaining near the southern edge.  The new
forecast track lies a little to the south of the center of the
guidance envelope in best agreement with the HCCA corrected
consensus model.

The depression should be in an environment of light shear and over
warm water for the next 24-36 h, which should allow steady
strengthening during that time.  The shear is forecast to increase
after 36 h to the point where it may at least slow development, and
this is reflected in slight changes from the previous forecast.  The
new intensity forecast is near the intensity consensus through 48 h,
and then is above the consensus from 72-120 h.  It should be noted
that the forecast still calls for the cyclone to become a hurricane
as it approaches the northern Leeward Islands.


Key Messages:

1. The depression is expected to strengthen and be a hurricane when
its moves near the northern Leeward Islands Thursday night and
Friday, although it is too soon to determine if there will be any
direct impacts in the islands. Interests there should ensure they
have their hurricane plan in place and monitor the progress of this
system.


FORECAST POSITIONS AND MAX WINDS

INIT  18/0300Z 13.7N  46.7W   30 KT  35 MPH
 12H  18/1200Z 14.4N  48.2W   35 KT  40 MPH
 24H  19/0000Z 15.3N  50.4W   45 KT  50 MPH
 36H  19/1200Z 16.2N  53.0W   50 KT  60 MPH
 48H  20/0000Z 17.3N  56.0W   55 KT  65 MPH
 72H  21/0000Z 19.5N  62.0W   65 KT  75 MPH
 96H  22/0000Z 21.5N  67.0W   70 KT  80 MPH
120H  23/0000Z 24.5N  70.5W   75 KT  85 MPH

$$
Forecaster Beven