413 
 WTNT43 KNHC 072046
 TCDAT3
 
 Tropical Depression Eight Discussion Number   2
 NWS National Hurricane Center Miami FL       AL082018
 500 PM AST Fri Sep 07 2018
 
 Satellite data and surface observations indicate that the low
 pressure system located just west of the coast of Africa has
 developed into a tropical depression.  Conventional satellite
 imagery shows a well-defined convective band has formed near the
 center, and microwave satellite imagery has hinted at the formation
 of an inner ring of convection.  The initial intensity of 30 kt
 and the central pressure of 1002 mb are based on surface
 observations from ships and the west coast of Africa. The depression
 currently has good cirrus outflow in all directions.
 
 The initial motion is 275/9.  During the next 3-4 days, the cyclone
 should move generally west-northwestward with an increase in forward
 speed on the south side of the subtropical ridge over the eastern
 Atlantic.  Near the end of the forecast period, a developing mid- to
 upper-level trough over the central Atlantic is expected to weaken
 the ridge and allow the cyclone to turn northwestward with a
 decrease in forward speed.  There is some spread in the guidance
 late in the period, with the UKMET and the Canadian models showing
 an earlier turn than the other models.   The new forecast track,
 which is similar to the previous track, is in best agreement with
 the TVCN and HCCA consensus models.
 
 The depression is in an environment of light to moderate easterly
 vertical shear and over sea surface temperatures of 27-28C.  This
 should allow at least steady strengthening, and rapid strengthening
 is possible based on the hints of the inner core in microwave
 imagery.  This portion of the intensity forecast has been increased
 to the upper edge of the intensity guidance, with the cyclone
 forecast to become a tropical storm in 12 h or less and a hurricane
 between 48-72 h.  After 72 h, the system should be over sea surface
 temperatures near 26C and encountering southwesterly vertical shear
 due to the aforementioned trough.  This should cause at least a
 gradual weakening.
 
 FORECAST POSITIONS AND MAX WINDS
 
 INIT  07/2100Z 13.2N  18.6W   30 KT  35 MPH
  12H  08/0600Z 13.5N  19.9W   35 KT  40 MPH
  24H  08/1800Z 13.9N  21.9W   45 KT  50 MPH
  36H  09/0600Z 14.4N  24.5W   55 KT  65 MPH
  48H  09/1800Z 14.9N  27.5W   60 KT  70 MPH
  72H  10/1800Z 16.5N  33.5W   70 KT  80 MPH
  96H  11/1800Z 18.0N  38.5W   65 KT  75 MPH
 120H  12/1800Z 20.5N  42.0W   60 KT  70 MPH
 
 $$
 Forecaster Beven