241 
 WTPZ42 KNHC 081437
 TCDEP2
 
 Hurricane Aletta Discussion Number  12
 NWS National Hurricane Center Miami FL       EP022018
 900 AM MDT Fri Jun 08 2018
 
 The remarkable intensification of Aletta has continued through this
 morning.  The eye has become clear and at times has been
 surrounded by a closed ring of cloud tops colder than -70 deg C.
 The initial intensity of 120 kt is based on a blend of subjective
 and objective Dvorak estimates.  It is noteworthy that the
 intensity of Aletta has increased by an estimated 60 kt in just 24
 hours since yesterday morning.
 
 The short-range intensity forecast is particularly difficult since
 there are no obvious reasons why Aletta should cease
 intensification.  Although the deep-layer wind shear is currently
 very low and SSTs are warm enough to support further
 intensification, nearly all of the intensity guidance indicates that
 Aletta should have reached its peak.  Recent microwave imagery does
 indicates that a secondary eyewall has not yet formed, however
 the resolution of the instruments could limit our ability to detect
 such a feature.  Given the low bias of the guidance for Aletta so
 far, the new forecast allows for some slight additional
 strengthening during the day today.  By 24 hours, moderate shear
 should cause the hurricane to begin weakening steadily, with rapid
 weakening occuring between 36 and 72 h while Aletta traverses a
 strong SST gradient.  Due to the higher initial intensity of Aletta,
 the official forecast is a little higher than the previous one for
 the first 24 hours, but very similar thereafter.
 
 Almost no change has been to the track forecast.  A broad
 upper-level trough over the eastern Pacific should cause Aletta to
 turn more toward the northwest in 24 to 36 h.  After Aletta rapidly
 weakens over the weekend, the lower-level trade winds will become
 the dominant steering flow, forcing the cyclone to turn back toward
 the west.  Excluding the ECMWF which does not have a realistic
 depiction of the major hurricane, the guidance has come into
 somewhat better agreement today and confidence in the track
 forecast has increased since yesterday.
 
 FORECAST POSITIONS AND MAX WINDS
 
 INIT  08/1500Z 15.8N 111.2W  120 KT 140 MPH
  12H  09/0000Z 16.3N 111.9W  125 KT 145 MPH
  24H  09/1200Z 17.0N 112.9W  110 KT 125 MPH
  36H  10/0000Z 17.9N 113.8W   85 KT 100 MPH
  48H  10/1200Z 18.6N 114.8W   65 KT  75 MPH
  72H  11/1200Z 19.5N 116.7W   35 KT  40 MPH
  96H  12/1200Z 20.0N 118.5W   25 KT  30 MPH...POST-TROP/REMNT LOW
 120H  13/1200Z 20.0N 119.5W   20 KT  25 MPH...POST-TROP/REMNT LOW
 
 $$
 Forecaster Zelinsky