579 
 WTPZ42 KNHC 061437
 TCDEP2
 
 Hurricane Olivia Discussion Number  24
 NWS National Hurricane Center Miami FL       EP172018
 800 AM PDT Thu Sep 06 2018
 
 Satellite imagery indicates that Olivia has a well-defined 20 n mi
 wide eye, although the eye is not quite as distinct as it was at
 the time of the previous special advisory.  The eye is inside of a
 central dense overcast with eyewall cloud tops as cold as -80C.
 Satellite intensity estimates are currently in the 100-115 kt
 range.  Based on these, the initial intensity is set at 105 kt, and
 it is possible that this is a little conservative.  The hurricane
 is now in a light vertical shear environment and is showing good
 cirrus outflow in the southwestern semicircle.
 
 The intensity guidance has been consistent in saying that Olivia
 should weaken due to a combination of decreasing sea surface
 temperatures along the forecast track and entrainment of dry air.
 The hurricane has not yet followed the guidance, and the current
 structure and convective trends suggest that this round of
 intensification may not be finished.  After 12 h, Olivia should move
 north of the 26C isotherm, and the cyclone should mostly traverse
 sea-surface temperatures of 25-26C for the remainder of the forecast
 period.  This development should start a weakening trend.  The new
 intensity forecast allows for 12 h of additional strengthening,
 followed by a gradual weakening that follows the overall trend of
 the intensity guidance.  However, the new forecast lies at the upper
 edge of the guidance, and thus most of the forecast intensities are
 higher than those in both the previous special and regular
 advisories.
 
 Water vapor imagery shows a large deep-layer ridge to the north of
 Olivia, and the large-scale models forecast the western end of the
 ridge to build westward during the next several days.  This pattern
 should steer the cyclone west-northwestward for the next 48 h or
 so, followed by a westward motion from 72-120 h.  The track guidance
 is in good agreement with this scenario, and the guidance is more
 tightly clustered than it was 24 h ago.  The new forecast track is
 similar to the previous track through 48 h, then it is nudged a
 little to the south of the previous track from 72-120 h.  The new
 track lies close to the various consensus models.
 
 
 FORECAST POSITIONS AND MAX WINDS
 
 INIT  06/1500Z 18.4N 127.2W  105 KT 120 MPH
  12H  07/0000Z 18.9N 129.2W  110 KT 125 MPH
  24H  07/1200Z 19.8N 131.8W  100 KT 115 MPH
  36H  08/0000Z 20.5N 134.4W   90 KT 105 MPH
  48H  08/1200Z 21.2N 137.0W   80 KT  90 MPH
  72H  09/1200Z 21.5N 142.0W   70 KT  80 MPH
  96H  10/1200Z 21.5N 146.5W   65 KT  75 MPH
 120H  11/1200Z 21.5N 150.5W   60 KT  70 MPH
 
 $$
 Forecaster Beven