019 
 WTPZ42 KNHC 110232
 TCDEP2
 
 Tropical Storm Aletta Discussion Number  22
 NWS National Hurricane Center Miami FL       EP022018
 800 PM PDT Sun Jun 10 2018
 
 Aletta is maintaining its sheared structure.  Although cloud tops
 have warmed over the past few hours, the tropical storm is still
 producing persistent convection in the northwestern quadrant. Dvorak
 classifications from TAFB and SAB have not changed since 6 hours
 ago, so the intensity has been held at 40 kt.  No change has been
 made to the intensity forecast.  Aletta has been moving along a
 tongue of moderately warm water, which may have allowed convection
 to persist up to this point, but the cyclone will soon cross a sharp
 SST gradient and enter into a much more stable environment.  Once
 that occurs, the cyclone will likely lose all convection and become
 a remnant low, gradually spinning down over the course of a few
 days.  While not explicitly shown in this forecast, it is possible
 that Aletta will dissipate by the middle to end of the week.
 
 The tropical storm has been moving toward the west-northwest, or
 285/6 kt, this evening, but a westward motion is expected to resume
 overnight.  All of the dynamical models continue to indicate that
 Aletta will be steered slowly westward by a mid-level ridge to the
 north for the next 24 to 36 hours.  After that time, a turn toward
 the west-southwest will likely occur as the low-level tradewinds
 become the dominant steering feature.  From day 3 onward, the
 cyclone is expected to become trapped in light low-level flow
 between a high pressure system to the northwest and Hurricane Bud to
 the east, so the NHC forecast shows little to no movement.  The
 official track forecast has been adjusted slightly northward for the
 first 36 hours due to Aletta's recent short-term west-northwestward
 motion, but is not significantly changed from the previous advisory
 and remains close to TVCN and HCCA.
 
 
 FORECAST POSITIONS AND MAX WINDS
 
 INIT  11/0300Z 16.8N 116.2W   40 KT  45 MPH
  12H  11/1200Z 16.9N 117.2W   35 KT  40 MPH
  24H  12/0000Z 16.9N 118.3W   30 KT  35 MPH
  36H  12/1200Z 16.7N 119.4W   25 KT  30 MPH...POST-TROP/REMNT LOW
  48H  13/0000Z 16.4N 119.9W   25 KT  30 MPH...POST-TROP/REMNT LOW
  72H  14/0000Z 16.2N 120.2W   20 KT  25 MPH...POST-TROP/REMNT LOW
  96H  15/0000Z 16.0N 120.5W   20 KT  25 MPH...POST-TROP/REMNT LOW
 120H  16/0000Z 16.0N 120.5W   15 KT  15 MPH...POST-TROP/REMNT LOW
 
 $$
 Forecaster Zelinsky