772 
 WTPZ45 KNHC 201457
 TCDEP5
 
 TROPICAL DEPRESSION TWENTY-E DISCUSSION NUMBER   1
 NWS NATIONAL HURRICANE CENTER MIAMI FL       EP202015
 1000 AM CDT TUE OCT 20 2015
 
 Satellite data indicate that deep convection associated with the
 area of low pressure a few hundred miles southeast of Puerto
 Escondido, Mexico, has become sufficiently well organized to
 designate the system as a tropical depression.  The circulation of
 the low has also become better defined according to an overnight
 ASCAT pass, though it could still be somewhat elongated to the
 south.  The depression's cloud pattern is characterized by
 interlocking convective bands, with the estimated low-level center
 underneath the eastward tip of the western band.  A Dvorak intensity
 estimate of T2.0 from TAFB is used to set the initial intensity at
 30 kt.
 
 Since the center location uncertainty has been high until
 very recently, the initial motion estimate is a rather uncertain
 280/02.  The track guidance is in very good agreement that a
 mid-level ridge over the Gulf of Mexico with an east-northeast to
 west-northwest orientation should impart a west-southwestward motion
 for about 24 hours.  A turn toward the west and west-northwest
 with some increase in forward speed is forecast by 36 hours once the
 ridge over the Gulf of Mexico shifts eastward.  When the cyclone
 reaches the western edge of ridge around 72 hours, it should turn
 northwestward.  The evolution of a deep longwave trough over the
 southwestern U.S. and northwestern Mexico is of critical
 importance to the track forecast after that time as the cyclone
 nears the southwestern coast of Mexico. There are differences
 between the models regarding the timing and strength of a shortwave
 trough dropping into the southwestern U. S. during this period,
 resulting in increasing spread of the track guidance after 72
 hours.  The track forecast is close to the multi-model consensus,
 but it is a little west of the GFS and ECMWF solutions beyond day 3.
 
 The large-scale environment around the cyclone is forecast to be
 quite conducive for intensification during the next few days, with
 SSTs to above 30 deg C, a rich moisture supply in the lower to
 middle troposphere, and very light vertical shear.  The main
 limiting factor should be how quickly the cyclone develops enough
 inner-core organization to potentially rapidly intensify.  Prior to
 landfall, an increase in southwesterly vertical shear and drier air
 associated with the mid-to upper-level trough to the northwest could
 result in weakening, with a peak intensity mostly likely between the
 72- and 96-hour points.  The NHC intensity forecast is above the
 multi-model consensus and in best agreement with the LGEM output
 until the forecast landfall.  Dissipation is shown after 96 hours,
 though it could occur sooner over the high terrain of the Sierra
 Madre Occidental.
 
 
 FORECAST POSITIONS AND MAX WINDS
 
 INIT  20/1500Z 13.3N  94.4W   30 KT  35 MPH
  12H  21/0000Z 13.0N  95.5W   35 KT  40 MPH
  24H  21/1200Z 12.8N  97.0W   45 KT  50 MPH
  36H  22/0000Z 12.9N  98.9W   55 KT  65 MPH
  48H  22/1200Z 13.9N 101.0W   70 KT  80 MPH
  72H  23/1200Z 16.3N 103.7W   85 KT 100 MPH
  96H  24/1200Z 20.5N 104.4W   50 KT  60 MPH...INLAND
 120H  25/1200Z...DISSIPATED
 
 $$
 Forecaster Kimberlain