184 
 WTNT44 KNHC 020300
 TCDAT4
 
 HURRICANE HERMINE DISCUSSION NUMBER  19
 NWS NATIONAL HURRICANE CENTER MIAMI FL       AL092016
 1100 PM EDT THU SEP 01 2016
 
 Reports from an Air Force Reserve Hurricane Hunter aircraft
 indicate that Hermine has gradually intensified since the last
 forecast advisory.  The plane measured 86-kt flight-level winds
 southeast of the center at 850 mb with SFMR and dropsonde data
 suggesting winds of at least 65 kt.  Based on these data and a
 earlier 983 mb central pressure, the initial intensity is set at 70
 kt.
 
 The initial motion remains 030/12.  The flow on the eastern side of
 a mid-level trough over the southeastern United States should cause
 Hermine to move north-northeastward to northeastward with an
 increase in forward speed during the next 36 hours.  The track
 guidance is tightly clustered during this period, and this part of
 the forecast track is an update of the previous track.  At 48 hours
 and beyond, Hermine is expected to interact with a baroclinic trough
 over the northeastern United States.  The track guidance become
 rather divergent during this period, with the GFS and ECMWF models
 showing a looping track close to the coast, while the UKMET and
 Canadian models show a slow motion somewhat farther offshore.  The
 new forecast track compromises between these solutions and shows a
 slow northeastward motion during this time.  Regardless of the exact
 track, Hermine should linger for several days near the northeastern
 U. S. coast as a vigorous low pressure system.
 
 A little more strengthening is possible during the last few hours
 before landfall.  After landfall, Hermine is expected to weaken as
 it crosses the southeastern United States, eventually emerging from
 the North Carolina coast as a tropical storm.  The cyclone is
 expected to re-intensify as an extratropical low during its
 interaction with the baroclinic trough.  The forecast intensities
 have been raised for this part of the forecast based on global model
 forecasts, and it is possible that they are a little conservative.
 Later in the forecast period, vertical shear decreases, and the
 cyclone could be situated over marginally warm waters.  Therefore
 there is the possibility of the system regaining some tropical
 characteristics in 4-5 days, although this remains speculative.
 
 KEY MESSAGES:
 
 1. As landfall occurs, it is important to not focus on the exact
 forecast track.  Hermine is an extremely asymmetric storm, with a
 large extent of dangerous winds, life-threatening storm surge, and
 flooding rains well to the east and southeast of the path of the
 center.
 
 2. Hermine is expected to become a post-tropical cyclone while still
 producing hazardous winds and storm surge over land.  NWS policy
 allows NHC to write advisories on and issue tropical storm
 watches and warnings for post-tropical cyclones, when the system
 continues to pose a significant threat to life and property.
 NHC and the NWS Eastern Region have decided that this option will be
 invoked for Hermine.  After Hermine becomes a post-tropical cyclone,
 NHC will continue to issue its full suite of advisory and warning
 products for as long as the system remains a significant threat to
 land.
 
 
 FORECAST POSITIONS AND MAX WINDS
 
 INIT  02/0300Z 29.7N  84.3W   70 KT  80 MPH
  12H  02/1200Z 31.5N  82.8W   60 KT  70 MPH
  24H  03/0000Z 33.6N  79.7W   45 KT  50 MPH...INLAND
  36H  03/1200Z 35.6N  75.7W   45 KT  50 MPH...INLAND
  48H  04/0000Z 37.0N  73.2W   50 KT  60 MPH...POST-TROP/EXTRATROP
  72H  05/0000Z 38.0N  72.5W   55 KT  65 MPH...POST-TROP/EXTRATROP
  96H  06/0000Z 39.0N  72.0W   55 KT  65 MPH...POST-TROP/EXTRATROP
 120H  07/0000Z 39.5N  70.5W   50 KT  60 MPH...POST-TROP/EXTRATROP
 
 $$
 Forecaster Beven