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TROPICAL STORM MATTHEW DISCUSSION NUMBER   2
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL142016
500 PM AST WED SEP 28 2016

Surface observations and aircraft data from earlier this afternoon
indicate that the circulation of Matthew has continued to become
better defined.  There has also been an increase in convection
just northeast of the center.  The initial intensity remains 50 kt
based on the earlier aircraft data.  The next Air Force Reserve
Hurricane Hunter mission into Matthew is scheduled for this evening.
Although the increase in convection suggests that the system may be
trying to establish an inner core, recent microwave and radar data
have not revealed a significant increase in organization or banding
so far.  The aircraft also did not report any pressure fall during
its mission. Based on these trends, little change in intensity is
predicted in the short-range, but warm waters and low shear are
expected to allow for steady strengthening while Matthew moves over
the eastern and central Caribbean during the next few days.  The
updated NHC intensity forecast is a little below the intensity
consensus through 24 hours, but is close to the consensus and the
statistical models after that time.

Matthew is moving westward to west-northwestward at about 16 kt.
The track forecast reasoning is unchanged from the previous
advisory.  The tropical cyclone should move generally westward
during the next 2 to 3 days to the south of a strong deep-layer
ridge over the western Atlantic.  The new NHC track forecast has
been nudged northward through 72 hours, to be closer to the new
model consensus.  After day 3, Matthew is expected to turn
northwestward as it nears the western portion of the ridge.  The
overall track envelope has shifted slightly eastward at days 4 and
5, and the NHC track has been adjusted accordingly.  It should
be noted that are still significant differences among the models in
how soon and how sharply Matthew turns northwestward and northward
late in the forecast period.  Users are reminded that the average
NHC track errors at days 4 and 5 are on the order of 180 and 240
miles, respectively.


FORECAST POSITIONS AND MAX WINDS

INIT  28/2100Z 13.8N  62.0W   50 KT  60 MPH
 12H  29/0600Z 14.1N  64.4W   50 KT  60 MPH
 24H  29/1800Z 14.4N  67.1W   55 KT  65 MPH
 36H  30/0600Z 14.4N  69.5W   65 KT  75 MPH
 48H  30/1800Z 14.1N  71.3W   70 KT  80 MPH
 72H  01/1800Z 14.2N  73.5W   80 KT  90 MPH
 96H  02/1800Z 15.8N  75.0W   90 KT 105 MPH
120H  03/1800Z 19.0N  76.0W   90 KT 105 MPH

$$
Forecaster Brown

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