Official Discussion issued by the National Hurricane Center

Thirteen (AL132017) DATA RELEASED: 9/5/2017 4:00:00 PM UTC

Copy of official data

Tropical Depression Thirteen Discussion Number   1
NWS National Hurricane Center Miami FL       AL132017
400 PM CDT Tue Sep 05 2017

The small area of low pressure in the southwestern Gulf of Mexico
has become better organized during the past several hours, with deep
convection forming over the center.  ASCAT data showed a
well-defined circulation with winds of about 30 kt.  Thus, a
tropical depression has formed, with maximum winds estimated at 30
kt.  While the cyclone is currently experiencing westerly shear,
most of the guidance indicate the shear should gradually lessen.
Combined with the very warm Gulf of Mexico waters, this should
promote strengthening.  The shear could increase again in a few
days, so the intensity forecast will be leveled off at that time.
The NHC wind speed prediction is near or slightly higher than the
model consensus, but could be conservative.

The depression has been drifting eastward during the day.  For the
next couple of days, the cyclone isn't expected to move much as it
is caught in an area of light winds in the mid-levels.  By Friday, a
ridge should build over Texas and the northwestern Gulf of Mexico,
which is likely to steer the system southwestward at a faster pace.
The NHC forecast is on the southern side of the guidance, since
models in that area tend to have a northward bias, between the
corrected consensus and the ECMWF.


FORECAST POSITIONS AND MAX WINDS

INIT  05/2100Z 22.4N  96.7W   30 KT  35 MPH
12H  06/0600Z 22.4N  96.3W   35 KT  40 MPH
24H  06/1800Z 22.2N  95.6W   45 KT  50 MPH
36H  07/0600Z 21.8N  95.2W   50 KT  60 MPH
48H  07/1800Z 21.4N  95.2W   55 KT  65 MPH
72H  08/1800Z 20.9N  95.6W   55 KT  65 MPH
96H  09/1800Z 19.7N  97.2W   30 KT  35 MPH...INLAND
120H  10/1800Z...DISSIPATED

$$
Forecaster Blake