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HURRICANE MATTHEW DISCUSSION NUMBER  31
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL142016
500 PM EDT WED OCT 05 2016

Data from an Air Force Hurricane Hunter plane a couple of hours ago
indicated that the structure of Matthew had not changed very much,
and the initial intensity remains at 105 kt. Another Hurricane
Hunter plane will be in the eye soon.   The environment continues to
be favorable for Matthew to restrengthen while it approaches the
the east coast of Florida during the next day or so.  After that
time, the shear is forecast to increase significantly, resulting in
gradual weakening of the hurricane.

Satellite images indicate that Matthew is moving toward the
northwest or 325 degrees at about 10 kt. The subtropical ridge over
the western Atlantic is still strong, and the flow pattern around
this ridge should continue to steer the hurricane toward the
northwest during the next day or two with no significant change in
forward speed. After that time, the ridge will shift eastward,
allowing Matthew to move northward very near or over the north
Florida east coast, and then near or to the east of the Georgia and
South Carolina coasts. By the end of the forecast period, models
diverge considerably, with the GFS moving the cyclone southwestward
toward land, and the ECMWF keeping Matthew over the Atlantic a good
distance from the coast. The NHC forecast keeps Matthew over water
in the middle of these two model solutions.

KEY MESSAGES:

1.  Matthew is likely to produce devastating impacts from storm
surge, extreme winds, and heavy rains in the Bahamas.  Please
consult statements from the meteorological service and other
government officials in that country.

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 specify impacts at
any one location.  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 within the hurricane warning area in Florida.
However, a small deviation to the right could keep the hurricane-
force winds offshore.  Similarly large variations in impacts are
possible in the hurricane watch area in northern Florida and
Georgia.

3.  Tropical storm or hurricane conditions could affect South
Carolina and North Carolina later this week or this weekend, even if
the center of Matthew remains offshore.  It is too soon to determine
what, if any, land areas might be directly affected by Matthew next
week.  At a minimum, dangerous beach and boating conditions are
likely along much of the U.S. east coast during the next several
days.

4.  The National Hurricane Center is issuing Potential Storm Surge
Flooding Maps, and Prototype Storm Surge Watch/Warning Graphics for
Matthew.  It is important to remember that the Potential Storm Surge
Flooding Map does not represent a forecast of expected inundation,
but rather depicts a reasonable worst-case scenario - the amount of
inundation that has a 10 percent chance of being exceeded.  In
addition, because the Flooding Map is based on inputs that extend
out only to about 72 hours, it best represents the flooding
potential in those locations within the watch and warning areas in
Florida and Georgia.

FORECAST POSITIONS AND MAX WINDS

INIT  05/2100Z 22.5N  75.7W  105 KT 120 MPH
 12H  06/0600Z 24.0N  76.9W  110 KT 125 MPH
 24H  06/1800Z 25.6N  78.5W  115 KT 130 MPH
 36H  07/0600Z 27.2N  79.8W  115 KT 130 MPH
 48H  07/1800Z 29.0N  80.8W  115 KT 130 MPH
 72H  08/1800Z 32.0N  79.5W   90 KT 105 MPH
 96H  09/1800Z 32.6N  76.4W   80 KT  90 MPH
120H  10/1800Z 30.0N  74.0W   65 KT  75 MPH

$$
Forecaster Avila

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