771 
 WTNT43 KNHC 082048
 TCDAT3
 
 Tropical Storm Leslie Discussion Number  50
 NWS National Hurricane Center Miami FL       AL132018
 500 PM AST Mon Oct 08 2018
 
 GOES-16 data indicate that Leslie has a small central dense overcast
 with an inner core trying to form on the last few visible images.
 Convection has also deepened somewhat, and the overall cloud pattern
 is becoming more symmetric.  All signs point to strengthening and
 the Dvorak estimates are increasing.   So for Leslie's 50th
 advisory, the wind speed is raised to 50 kt, near the CIMSS ADT
 value.
 
 Leslie is moving southeastward at about 12 kt; an unusually fast
 pace for this direction.  The storm is forecast to slow down
 somewhat and turn toward the south-southeast during the next day or
 two as the cyclone separates from the mid-latitude flow temporarily
 and becomes steered by a mid-level ridge over the central Atlantic.
 Fortunately the ridge isn't strong enough for Leslie to move
 westward again, and the models all eject Leslie northeastward
 because of a deepening trough over the eastern Atlantic.  There has
 been a notable trend southward through 48 hours, and the official
 forecast follows that idea.   The forecast becomes a nightmare at
 long range, however, with very little agreement on whether Leslie is
 accelerated ahead of the trough, like the latest FV3GFS, or gets
 left behind again, like the ECMWF.  These differences result in a
 1200 mile spread of the historically reliable models by day 5,
 resulting in a very low confidence forecast. The bulk of the
 guidance is now indicating that the "left behind" option is becoming
 more likely, but continuity dictates making forecast changes in
 smaller chunks. So the official forecast is much slower and farther
 south at long range, but is well north of the latest model
 consensus.  Further southward adjustments could be required if model
 trends continue.
 
 Interestingly, model guidance is becoming more certain on Leslie
 becoming a hurricane again as it moves over warmer (but still
 marginally warm) waters, into a lighter-shear and higher mid-level
 humidity enviroment.  This makes some sense given that the track is
 shifting southward and Leslie should finally move over a warmer
 portion of the subtropical Atlantic that it hasn't touched yet. Thus
 the intensity forecast is higher than the previous one, and the
 corrected-consensus models even suggest category 2 as a peak
 intensity is possible.  By day 5, increasing shear and cooler waters
 should weaken Leslie, and it could be undergoing extratropical
 transition at that time.
 
 
 FORECAST POSITIONS AND MAX WINDS
 
 INIT  08/2100Z 33.8N  45.8W   50 KT  60 MPH
  12H  09/0600Z 32.5N  44.4W   55 KT  65 MPH
  24H  09/1800Z 30.6N  43.2W   55 KT  65 MPH
  36H  10/0600Z 28.9N  42.5W   60 KT  70 MPH
  48H  10/1800Z 28.2N  41.7W   65 KT  75 MPH
  72H  11/1800Z 29.5N  37.0W   75 KT  85 MPH
  96H  12/1800Z 33.5N  26.5W   75 KT  85 MPH
 120H  13/1800Z 37.0N  17.0W   60 KT  70 MPH
 
 $$
 Forecaster Blake