058 
 WTNT41 KNHC 222037
 TCDAT1
 
 TROPICAL DEPRESSION FIONA DISCUSSION NUMBER  24
 NWS NATIONAL HURRICANE CENTER MIAMI FL       AL062016
 500 PM AST MON AUG 22 2016
 
 A new burst of convection has developed near the center of Fiona
 during the past several hours.  However, this increase was not
 significant enough to affect the subjective satellite intensity
 estimates, which remain at 30 kt.  This is also in good
 agreement with earlier ASCAT data.
 
 The dynamical models forecast that the current westerly vertical
 shear will subside somewhat by 36-48 hours as Fiona moves under an
 upper-level trough into an area of easterly upper-level winds to
 the north of the trough.  By 72 hours, the models forecast the
 cyclone or its remnants to encounter a second trough, which should
 produce another round of strong southwesterly shear. The
 intensity forecast is still based on the premise that the cyclone
 will not be able to respond to the brief period of more favorable
 conditions, and it calls for Fiona to gradually decay and become a
 remnant low in about 48 hours. This should be followed by the system
 weakening to a trough after 96 hours.
 
 The initial motion is 285/15.  The guidance remains in good
 agreement on the forecast track through 72 hours, with Fiona moving
 west-northwestward to northwestward toward a weakness in the
 subtropical ridge.  Beyond that time, the guidance diverges,
 with the ECMWF turning the remnants of the system northeastward
 while the GFS and UKMET show a westward turn.  The new forecast
 track is again a compromise between these extremes in showing a slow
 north-northwestward motion.  Overall, the track guidance has
 shifted westward since the previous advisory, and as a result the
 forecast track has also shifted a little to the west.
 
 FORECAST POSITIONS AND MAX WINDS
 
 INIT  22/2100Z 25.1N  61.3W   30 KT  35 MPH
  12H  23/0600Z 25.6N  63.1W   30 KT  35 MPH
  24H  23/1800Z 26.5N  65.0W   30 KT  35 MPH
  36H  24/0600Z 27.4N  66.7W   30 KT  35 MPH
  48H  24/1800Z 28.3N  67.9W   25 KT  30 MPH...POST-TROP/REMNT LOW
  72H  25/1800Z 30.5N  69.0W   25 KT  30 MPH...POST-TROP/REMNT LOW
  96H  26/1800Z 31.5N  70.0W   25 KT  30 MPH...POST-TROP/REMNT LOW
 120H  27/1800Z...DISSIPATED
 
 $$
 Forecaster Beven
 
 

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