521 
 WTNT41 KNHC 300254
 TCDAT1
 
 TROPICAL STORM JOAQUIN DISCUSSION NUMBER   9
 NWS NATIONAL HURRICANE CENTER MIAMI FL       AL112015
 1100 PM EDT TUE SEP 29 2015
 
 The cloud pattern of Joaquin has continued to become better
 organized this evening.  The low-level center is located within the
 northwestern portion of the deep convection and the outflow has
 continued to expand over the northern semicircle, which suggests
 that the shear continues to decrease.  The latest satellite
 intensity estimates from TAFB and SAB are T3.5 or 55 kt on the
 Dvorak scale.  Based on the earlier reconnaissance aircraft data and
 the continued increase in organization this evening, the initial
 wind speed has been raised to 60 kt.  Joaquin is forecast to be over
 warm water and in an increasingly favorable upper-level wind pattern
 during the next day or so.  These conditions favor intensification
 and the NHC forecast calls for Joaquin to become a hurricane within
 the next 12 hours.  The upper-level winds are shown by the global
 models to become quite conducive for strengthening by 36 hours as an
 upper-level anticyclone builds over the system, and additional
 strengthening is anticipated.  The new NHC forecast is a bit
 higher than the previous advisory, and is close to the IVCN
 intensity consensus aid.  It should be noted, that the UKMET, GFS,
 and ECMWF models all significantly deepen Joaquin during the next
 few days, and the NHC forecast could be somewhat conservative.
 
 Joaquin is moving west-southwestward at about 5 kt.  This general
 motion is forecast to continue during the next 24-36 hours while the
 cyclone remains to the southwest of a weak mid-level ridge. During
 this time, the center of Joaquin is forecast to move near or over
 portions of the Central Bahamas.  After 48 hours, a deepening mid-
 to upper-level trough over the southeastern United States is
 expected to cause a turn toward the north or north-northeast with an
 increase in forward speed.  There remains large spread in the
 guidance at days 4 and 5, with the ECMWF showing a northeastward
 motion toward Bermuda.  Meanwhile, the 18Z GFS shifted significantly
 westward and is close to the UKMET and HWRF, which are along the
 western edge of the guidance envelope.  The NHC track has been
 shifted westward, but it is not as far west as the multi-model
 consensus. The new track is fairly close to the ECMWF-Ensemble Mean.
 
 The government of the Bahamas has issued a Hurricane Watch for the
 Central Bahamas.  Additional watches or warnings may be required
 early Wednesday.
 
 At this time it is very hard to gauge the long-range potential
 impacts of Joaquin in the United States.  The environmental steering
 currents are complex and are not being handled in a consistent
 manner by the forecast models.  A wide range of outcomes are
 possible and it is simply too soon to say what impacts, if any,
 Joaquin will have on the United States.
 
 FORECAST POSITIONS AND MAX WINDS
 
 INIT  30/0300Z 25.8N  71.7W   60 KT  70 MPH
  12H  30/1200Z 25.5N  72.4W   70 KT  80 MPH
  24H  01/0000Z 25.2N  73.3W   75 KT  85 MPH
  36H  01/1200Z 24.8N  74.1W   80 KT  90 MPH
  48H  02/0000Z 24.9N  74.5W   85 KT 100 MPH
  72H  03/0000Z 26.7N  74.0W   90 KT 105 MPH
  96H  04/0000Z 31.3N  72.5W   85 KT 100 MPH
 120H  05/0000Z 35.5N  72.0W   80 KT  90 MPH
 
 $$
 Forecaster Brown