625 
 WTNT41 KNHC 220232
 TCDAT1
 
 TROPICAL DEPRESSION FIONA DISCUSSION NUMBER  21
 NWS NATIONAL HURRICANE CENTER MIAMI FL       AL062016
 1100 PM AST SUN AUG 21 2016
 
 Deep convection continues to sputter near the center of Fiona, with
 each successive burst a little smaller and less organized than the
 previous ones that sheared off in the strong westerly upper-level
 winds.  Given that earlier ASCAT data only showed a few 35-kt winds
 and the decrease in convective organization since that time, the
 initial intensity is set to 30 kt, which is also in agreement with
 the latest TAFB Dvorak estimate.
 
 The intensity forecast remains tricky.  Fiona has been slowly
 weakening due to about 30 kt of westerly wind shear and mid-level
 dry air, and the NHC forecast shows the cyclone becoming a remnant
 low in the next 24 to 36 hours.  However, the shear is forecast to
 decrease to 10 kt or less by 48 hours and the mid-levels begin to
 moisten according to the SHIPS model forecast.  Therefore, if Fiona
 can survive the next 24 to 36 hours, the environment will become
 more conducive for restrengthening or maintaining the system as a
 tropical cyclone.  The global models still disagree on the fate of
 Fiona, with the ECMWF showing dissipation in 2-3 days while the GFS
 and UKMET keep Fiona as a weak low through 5 days.  The NHC forecast
 maintains continuity and indicates dissipation in 5 days as a
 compromise between these possibilities.
 
 The initial motion estimate is 290/16, as Fiona continues to move
 quickly west-northwestward under the influence of a low- to mid-
 level ridge over the central Atlantic.  Fiona, or its remnants, will
 move around the western side of the ridge during the next several
 days, which should result is a poleward turn and a decrease in
 forward speed.  The new NHC forecast is largely an update of the
 previous one through dissipation.  There continues to be a fair
 amount of cross-track spread late in the period, and the NHC track
 still favors the GFS solution and lies to the right of the multi-
 model consensus.
 
 FORECAST POSITIONS AND MAX WINDS
 
 INIT  22/0300Z 23.8N  56.6W   30 KT  35 MPH
  12H  22/1200Z 24.5N  58.6W   30 KT  35 MPH
  24H  23/0000Z 25.3N  60.9W   30 KT  35 MPH
  36H  23/1200Z 26.2N  62.8W   30 KT  35 MPH...POST-TROP/REMNT LOW
  48H  24/0000Z 27.0N  64.5W   30 KT  35 MPH...POST-TROP/REMNT LOW
  72H  25/0000Z 29.0N  67.0W   30 KT  35 MPH...POST-TROP/REMNT LOW
  96H  26/0000Z 30.5N  68.0W   30 KT  35 MPH...POST-TROP/REMNT LOW
 120H  27/0000Z...DISSIPATED
 
 $$
 Forecaster Brennan