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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