765 
 WTNT44 KNHC 050256
 TCDAT4
 
 HURRICANE MATTHEW DISCUSSION NUMBER  28
 NWS NATIONAL HURRICANE CENTER MIAMI FL       AL142016
 1100 PM EDT TUE OCT 04 2016
 
 Hurricane Matthew made landfall along the extreme eastern coast of
 Cuba near Juaco around 0000 UTC this evening, and the eye is just
 now moving off of the northeastern coast of Cuba. Some weakening has
 occurred due to interaction with the mountains of eastern Cuba and
 western Haiti. However, latest reports from an Air Force Reserve
 reconnaissance aircraft indicate that the central pressure hasn't
 risen much and that the maximum winds have only decreased to an
 estimated 115 kt, keeping Matthew a dangerous category four
 hurricane.
 
 Radar and recon fixes indicate that Matthew is moving slightly west
 of due north, or 350/07 kt. Matthew is expected to begin turning
 toward the north-northwest during the next 12 hours or so, followed
 by a northwestward motion in 24-48 hours as the large ridge to the
 north of the powerful hurricane begins to build westward across the
 southeastern United States in response to a broad trough over the
 central U.S. weakening and lifting out to the northeast. The next
 upstream weather system that will affect the steering currents
 surrrounding Matthew is a large trough currently approaching the
 northwestern U.S. and southwestern Canada. That system is forecast
 to dig southeastward and amplify over the central U.S. during next
 several days, resulting in significant ridging downstream over the
 northeastern United States. As the next ridge builds and lifts
 northward, Matthew is expected to turn northward as well by 72
 hours, and turn northeastward after that as the aforementioned
 trough moves eastward into the eastern United States by 96-120
 hours.  The official forecast track remains close to a blend of the
 GFS and ECMWF models.
 
 The current 10-15 kt of northwesterly vertical wind shear is
 forecast to weaken to around 5 kt by 36-48 hours while Matthew is
 moving over the warm waters of the Gulf Stream, where SSTs are
 expected to be near 30 deg C.  That combination, along with high
 mid-level humidity, should enable Matthew to maintain category four
 status, although eyewall replacement cycles, which can not be
 forecast with any skill, could result in fluctuations in the
 intensity not shown by the official forecast. By 72 hours and
 beyond, steadily increasing vertical wind shear is expected to
 induce gradual weakening. The official intensity forecast is close
 to but slightly above the consensus model IVCN.
 
 KEY MESSAGES:
 
 1.  Matthew is likely to produce devastating impacts from storm
 surge, extreme winds, heavy rains, flash floods, and/or mudslides in
 portions of the warning areas in Haiti, Cuba, and the Bahamas.
 Please consult statements from the meteorological services and other
 government officials in those countries.
 
 2.  When a hurricane is forecast to take a track roughly parallel
 to a coastline, as Matthew is forecast to do from Florida through
 South Carolina, it becomes very difficult to estimate impacts this
 far in advance.  For example, only a small deviation of the track to
 the left of the NHC forecast could bring the core of a major
 hurricane onshore, while a small deviation to the right could keep
 all of the hurricane-force winds offshore.  It will likely take
 another day or so for the potential impacts of Matthew in the United
 States to clarify.
 
 3.  Tropical storm or hurricane conditions could affect portions of
 Florida north of the current Hurricane Watch area, Georgia, South
 Carolina, and North Carolina  later this week or this weekend, even
 if the center of Matthew remains offshore.  It is too soon to
 specify what, if any, direct impacts Matthew might have on the
 remainder of the U.S. east coast farther to the north.  At a
 minimum, very dangerous beach and boating conditions are likely
 along much of the U.S. east coast later this week and weekend.
 
 FORECAST POSITIONS AND MAX WINDS
 
 INIT  05/0300Z 20.4N  74.4W  115 KT 130 MPH
  12H  05/1200Z 21.7N  74.8W  115 KT 130 MPH
  24H  06/0000Z 23.3N  76.0W  115 KT 130 MPH
  36H  06/1200Z 25.0N  77.6W  115 KT 130 MPH
  48H  07/0000Z 26.7N  79.0W  115 KT 130 MPH
  72H  08/0000Z 30.3N  80.8W  100 KT 115 MPH
  96H  09/0000Z 33.2N  78.1W   85 KT 100 MPH
 120H  10/0000Z 37.0N  72.0W   70 KT  80 MPH
 
 $$
 Forecaster Stewart