Potential Tropical Cyclone Seven Discussion Number   1
NWS National Hurricane Center Miami FL       AL072017
500 PM EDT Sun Aug 06 2017

Surface and scatterometer data indicate that the broad area of
low pressure over the northwestern Caribbean Sea still lacks a
well-defined center of circulation.  However, this system is
likely to become a tropical storm before reaching the coast of the
Yucatan Peninsula late tomorrow, and advisories are being initiated
to enable the issuance of a tropical storm warning and watch for
Yucatan and Belize respectively.  The scatterometer pass and NOAA
data buoy observations indicate that the maximum winds are near
30 kt.  The disturbance has been experiencing westerly vertical
shear due to a nearby upper-level low and this has been inhibiting
development.  Global model predictions show that this low will soon
dissipate and an upper-level anticyclone will become established
over the area.  Therefore, strengthening is likely with the main
impediment being interaction with land.  The official intensity
forecast is a little above the model consensus.  It should be
noted that the system could become a hurricane between 72 and 96
hours, i.e. prior to reaching the Gulf coast of Mexico.

Since the center lacks definition, the initial location and motion
are quite uncertain, and my best guess for the current motion is
290/10.  The steering pattern for the disturbance/tropical cyclone
is expected to be fairly straightforward and persistent for the
next few days.  A general west-northwestward track is expected to
continue until landfall in mainland Mexico.  The official track
forecast is generally a blend of the latest GFS and ECMWF solutions.

FORECAST POSITIONS AND MAX WINDS

INIT  06/2100Z 15.6N  82.0W   30 KT  35 MPH...POTENTIAL TROP CYCLONE
12H  07/0600Z 16.6N  83.6W   35 KT  40 MPH...TROPICAL CYCLONE
24H  07/1800Z 18.0N  85.9W   45 KT  50 MPH
36H  08/0600Z 19.0N  88.0W   45 KT  50 MPH...INLAND
48H  08/1800Z 19.9N  90.1W   35 KT  40 MPH...INLAND
72H  09/1800Z 21.0N  93.8W   60 KT  70 MPH...OVER WATER
96H  10/1800Z 21.2N  97.8W   60 KT  70 MPH...INLAND
120H  11/1800Z...DISSIPATED

$$
Forecaster Pasch