979 
 WTNT41 KNHC 022055
 TCDAT1
 
 HURRICANE JOAQUIN DISCUSSION NUMBER  20
 NWS NATIONAL HURRICANE CENTER MIAMI FL       AL112015
 500 PM EDT FRI OCT 02 2015
 
 Satellite imagery and reports from an Air Force Reserve Hurricane
 Hunter aircraft indicate that Joaquin has weakened a little since
 the last advisory, with the central pressure rising to 942 mb.
 Based on this, the initial intensity is decreased to 110 kt.
 Subsequent observations from San Salvador Island and dropsondes from
 a NASA aircraft suggest the pressure is still near 942 mb.  While
 the hurricane continues to produce cold cloud tops in the eyewall,
 the convective pattern currently looks ragged in infrared imagery,
 and only occasional hints of a eye are apparent in visible imagery.
 
 The initial motion is now 360/6.  Water vapor imagery shows a mid-
 to upper-level ridge to the north and northeast of the hurricane,
 while a deep-layer trough and associated surface front are located
 over the southeastern United States.  This system is forecast to
 move slowly eastward with a non-tropical low forming along the
 front during the next couple of days.  While this occurs, a mid- to
 upper-level low currently centered near 30N 64W should move
 west-northwestward to the north of Joaquin.  These developments
 should steer Joaquin northward for the next few hours, followed by
 a turn toward the northeast.  The track guidance is now in good
 agreement that Joaquin will move generally northeastward between
 the United States and Bermuda, with a short-lived northward turn in
 the 48-72 hour period.  Eventually, the cyclone is expected to
 move into the westerlies and move quickly east-northeastward across
 the North Atlantic.  The new forecast track is similar to the
 previous forecast and now lies near the consensus models.
 
 Joaquin is forecast to remain in an environment of light vertical
 wind shear for another 12-24 hours or so, and during this time some
 fluctuations in intensity are possible. After 24 hours, the shear is
 forecast to increase, which should start a steady weakening.
 Extratropical transition is expected to begin around 96 hours and be
 complete by 120 hours. Overall, the new intensity forecast is an
 update of the previous advisory and lies near the intensity
 consensus.
 
 
 KEY MESSAGES:
 
 1.  Hurricane conditions over portions of the Bahamas should
 continue for several more hours.
 
 2.  Swells from a hurricane moving even far offshore of the U.S.
 east coast can still cause life-threatening surf and rip-current
 conditions.  Please see products from your local National Weather
 Service forecast office.  For information on the heavy rains
 occurring along the U.S. Atlantic states that are mostly unrelated
 to Hurricane Joaquin, please see products from the NWS Weather
 Prediction Center and your local forecast office.
 
 3. Since the direct threat of hurricane conditions to land areas
 is diminishing significantly, this will be the last set of key
 messages unless the threat increases.
 
 
 FORECAST POSITIONS AND MAX WINDS
 
 INIT  02/2100Z 24.1N  74.7W  110 KT 125 MPH
  12H  03/0600Z 25.1N  73.9W  110 KT 125 MPH
  24H  03/1800Z 26.9N  72.1W  105 KT 120 MPH
  36H  04/0600Z 29.2N  70.0W  100 KT 115 MPH
  48H  04/1800Z 31.7N  68.7W   90 KT 105 MPH
  72H  05/1800Z 36.5N  67.0W   75 KT  85 MPH
  96H  06/1800Z 40.5N  60.5W   65 KT  75 MPH
 120H  07/1800Z 45.0N  46.0W   55 KT  65 MPH...POST-TROP/EXTRATROP
 
 $$
 Forecaster Beven