290 
 WTPZ44 KNHC 310247
 TCDEP4
 
 TROPICAL STORM GUILLERMO DISCUSSION NUMBER   5
 NWS NATIONAL HURRICANE CENTER MIAMI FL       EP092015
 800 PM PDT THU JUL 30 2015
 
 
 Microwave and conventional satellite imagery indicate that
 Guillermo is continuing to become better organized.  The microwave
 imagery shows a developing eye, which has occasionally appeared in
 visible and infrared imagery.  Satellite intensity estimates are
 55 kt from TAFB and SAB, and the latest intensity estimate from
 the CIMSS Advanced Dvorak Technique is 65 kt.  Based on these, the
 initial intensity is increased to 60 kt.
 
 Guillermo has turned to the right during the past several hours
 with the initial motion now 305/12.  Other than that, there is
 little change in the forecast philosophy.  The subtropical ridge
 north of the storm is forecast to strengthen slightly, causing
 Guillermo to accelerate west-northwestward during the next 36
 hours. After that time, a mid- to upper-level low well west of
 California is expected to produce a break in the ridge, which should
 cause the cyclone to slow down and turn more northward by day 5.
 The forecast track from 0 to 72 hours has been adjusted northward
 based on the initial position and motion.  After 72 hours, the
 forecast guidance has again shifted to the left or west, and the
 forecast track has also been moved in that direction.  However,
 this part of the forecast lies to the north of the various
 consensus models.
 
 The developing eye seen in microwave imagery shows that the
 structure of Guillermo is conducive for additional rapid
 intensification.  Also, the Rapid Intensification Index of the SHIPS
 model shows a 50 percent chance of a 30 kt increase in intensity
 during the next 24 hours.  Based on this, the intensities during the
 first 48 hours of the forecast have been increased over those of the
 previous advisory, and this part of the forecast lies near the upper
 edge of the intensity guidance. After 48 hours, the cyclone will
 move over decreasing sea surface temperatures and possibly encounter
 westerly vertical wind shear.  This combination is expected to
 cause the cyclone to weaken below hurricane strength by 120 hours.
 It should be noted that the early part of the intensity forecast is
 of low confidence due to the uncertainties associated with rapid
 intensification, and the later part is of low confidence due to
 uncertainties in how much shear Guillermo will encounter.
 
 
 FORECAST POSITIONS AND MAX WINDS
 
 INIT  31/0300Z 10.8N 129.3W   60 KT  70 MPH
  12H  31/1200Z 11.4N 131.4W   70 KT  80 MPH
  24H  01/0000Z 12.3N 134.5W   80 KT  90 MPH
  36H  01/1200Z 13.1N 137.5W   90 KT 105 MPH
  48H  02/0000Z 13.9N 139.8W   95 KT 110 MPH
  72H  03/0000Z 15.5N 143.5W   85 KT 100 MPH
  96H  04/0000Z 16.5N 146.5W   70 KT  80 MPH
 120H  05/0000Z 18.0N 149.5W   55 KT  65 MPH
 
 $$
 Forecaster Beven