190 
 WTNT44 KNHC 290251
 TCDAT4
 
 TROPICAL STORM MATTHEW DISCUSSION NUMBER   3
 NWS NATIONAL HURRICANE CENTER MIAMI FL       AL142016
 1100 PM AST WED SEP 28 2016
 
 Matthew crossed a portion of the Lesser Antilles today, and
 tropical-storm-force winds were experienced in various islands for
 several hours.  The strongest winds appeared to have occurred in
 Martinique which was located in the northeastern quadrant of the
 storm.  An Air Force plane currently investigating Matthew measured
 a peak wind at 850-mb of 73 kt, while the SFMR instrument measured
 54 kt. The minimum central pressure was 1004 mb. There are no signs
 of an inner core yet, but the cloud pattern has increased in
 organization, and the initial intensity was adjusted upward to 55
 kt.
 
 Matthew is forecast to move over warm waters and relatively low
 shear during the next few days, and these conditions should lead to
 gradual strengthening.  There is a possibility, however, that
 Matthew encounters some westerly shear in the central Caribbean well
 south of Haiti in a day or two. This is an area climatologically
 unfavorable for storms to intensify, and Matthew could reduce its
 rate of strengthening there.  After that, most of the models show a
 more conducive upper-level environment, and Matthew could intensify
 at a faster rate. The NHC forecast is not very different from its
 predecessor and follows closely the intensity consensus.
 
 Fixes from an Air Force plane indicate that Matthew is moving
 toward the west or 270 degrees at 13 kt.  A strong subtropical
 ridge over the Atlantic is steering Matthew westward, and some
 models even move the cyclone south of due west. Most of the guidance
 is very consistent with this track during the next 48 hours. After
 that time, guidance becomes more divergent, but in general, all
 models turn the cyclone toward the northwest and north. Of the
 historically reliable models, the westernmost track is the ECMWF
 ensemble mean while the easternmost is the HWRF. The NHC track
 forecast is in the middle of the TVCX and TVCN multi-model
 consensus, and does not depart very much from the previous official
 forecast.
 
 There will be very interesting days ahead as Matthew moves toward
 the central and western Caribbean Sea, and 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  29/0300Z 13.9N  63.1W   55 KT  65 MPH
  12H  29/1200Z 14.3N  65.3W   60 KT  70 MPH
  24H  30/0000Z 14.4N  67.9W   65 KT  75 MPH
  36H  30/1200Z 14.3N  70.0W   70 KT  80 MPH
  48H  01/0000Z 14.1N  71.5W   75 KT  85 MPH
  72H  02/0000Z 14.5N  73.5W   75 KT  85 MPH
  96H  03/0000Z 16.8N  75.0W   90 KT 105 MPH
 120H  04/0000Z 20.0N  75.5W   90 KT 105 MPH
 
 $$
 Forecaster Avila