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Tropical Depression Six Special Discussion Number   1
NWS National Hurricane Center Miami FL       AL062017
600 AM EDT Mon Jul 31 2017

Radar imagery from the NWS Tampa Bay WSR-88D indicates that shower
and thunderstorm activity associated with the small low pressure
area over the eastern Gulf of Mexico have persisted and become
better organized overnight.  Earlier ASCAT data showed that the
system has a well-defined circulation and winds of at least 30 kt
over a small area to the north and northwest of the center. Based on
these data, advisories are being initiated on a 30-kt tropical
depression.  The depression is currently embedded within an area of
moderate to strong northwesterly shear.  Although the upper-level
winds could become a little more favorable for strengthening, the
depression is expected to move inland over the west-central Florida
peninsula later today, and no significant change in wind speed is
predicted.  After the depression moves over the western Atlantic,
increasing westerly shear is forecast to prevent intensification.
This scenario is in agreement with the GFS and ECMWF models, which
show the system weakening and likely dissipating in 3 to 4 days, or
perhaps sooner.

The depression is moving eastward at about 7 kt. The cyclone is
embedded within the southern portion of a deep-layer trough that
extends southwestward along the U.S. east coast. This pattern should
steer the system eastward today, then northeastward with some
increase in forward speed through dissipation. The track guidance is
in relatively good agreement on this scenario, although there are
some differences in how fast the system will accelerate
northeastward. For now, the NHC forecast lies between the faster
HWRF and GFS solutions, and the slower ECMWF.

The primary threat with this system is expected to be locally heavy
rainfall across portions of the Florida peninsula during the next
couple of days. Due to the uncertainty in the intensity forecast, a
Tropical Storm Watch has been issued for a portion of the west-
central coast of Florida.

FORECAST POSITIONS AND MAX WINDS

INIT  31/1000Z 27.7N  83.5W   30 KT  35 MPH
 12H  31/1800Z 27.7N  82.4W   30 KT  35 MPH
 24H  01/0600Z 28.3N  80.6W   30 KT  35 MPH
 36H  01/1800Z 29.8N  78.6W   30 KT  35 MPH
 48H  02/0600Z 31.6N  76.5W   30 KT  35 MPH
 72H  03/0600Z 34.5N  72.0W   30 KT  35 MPH
 96H  04/0600Z...DISSIPATED

$$
Forecaster Brown

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