676 
 WTNT41 KNHC 220842
 TCDAT1
 
 TROPICAL DEPRESSION FIONA DISCUSSION NUMBER  22
 NWS NATIONAL HURRICANE CENTER MIAMI FL       AL062016
 500 AM AST MON AUG 22 2016
 
 Although deep convection has continued to pulse near the center of
 Fiona, recent scatterometer wind data and various satellite
 classifications support maintaining the small but remarkably
 resilient cyclone as a 30-kt tropical depression. The intensity
 forecast still remains something of an enigma. Strong westerly wind
 shear is forecast to persist for the next 12-18 hours, after which
 the upper-level winds relax somewhat and become a little more
 conducive for strengthening to occur. However, dry mid-level
 air of 40-50 percent humidity is also forecast to surround the
 cyclone, which could act to hinder the development of persistent
 deep convection for the next 24-36 hours. Therefore, if Fiona
 can survive the aforementioned hostile conditions during the next 24
 hours or so, then some restrengthening or maintaining the status as
 a tropical cyclone is possible.  The global models still disagree on
 the future of Fiona and have flipped-flopped, with the ECMWF no
 longer showing dissipation in 5 days, which is similar to the UKMET
 solution, whereas the GFS now shows Fiona degenerating into an open
 trough between 96-120 hours. The NHC forecast maintains continuity
 and indicates dissipation in 5 days as a compromise between these
 possibilities.
 
 The initial motion estimate remains 290/16 kt. Although there is
 uncertainty in the future status of Fiona, the NHC model guidance
 is in pretty good agreement on the track of the cyclone for the
 next 72 hours. The small cyclone is forecast to move quickly
 west-northwestward around the southwestern periphery of a
 deep-layer ridge for the next 3 days, and then slow down
 considerably on day 4 and turn northward into a weakness in the
 ridge. The new official forecast track is basically just an update
 of the previous track through 72 hours, and then is a little to
 the right of the previous forecast on day 4, which leans closer to
 the solutions of the various consensus models.
 
 FORECAST POSITIONS AND MAX WINDS
 
 INIT  22/0900Z 24.4N  58.4W   30 KT  35 MPH
  12H  22/1800Z 25.0N  60.2W   30 KT  35 MPH
  24H  23/0600Z 25.8N  62.3W   30 KT  35 MPH
  36H  23/1800Z 26.6N  64.1W   30 KT  35 MPH...POST-TROP/REMNT LOW
  48H  24/0600Z 27.6N  65.6W   30 KT  35 MPH...POST-TROP/REMNT LOW
  72H  25/0600Z 29.8N  67.7W   30 KT  35 MPH...POST-TROP/REMNT LOW
  96H  26/0600Z 31.3N  67.7W   30 KT  35 MPH...POST-TROP/REMNT LOW
 120H  27/0600Z...DISSIPATED
 
 $$
 Forecaster Stewart