198 
 WTPZ43 KNHC 290249
 TCDEP3
 
 HURRICANE JIMENA DISCUSSION NUMBER  10
 NWS NATIONAL HURRICANE CENTER MIAMI FL       EP132015
 800 PM PDT FRI AUG 28 2015
 
 Jimena is rapidly intensifying.  Conventional satellite imagery
 shows that the hurricane's well-defined eye has warmed and
 contracted since the last advisory.  Its central dense overcast,
 consisting of very cold cloud top temperatures, has also become
 increasingly more symmetric.  Aside from Jimena's core features,
 outer bands surrounding the cyclone have also increased and become
 better defined.  Dvorak classifications were T5.5/102 kt from TAFB
 and SAB at 0000 UTC and the latest UW-CIMSS ADT value is 6.2/120 kt.
 A blend of these data are used to arrive at an intensity estimate of
 110 kt, making Jimena the fourth major hurricane of the season.
 
 The initial motion estimate is 275/10, although the cyclone appears
 to have recently experienced a southward trochoidal wobble. Directly
 underneath a subtropical ridge to the north, Jimena should maintain
 a general westward course for the next 12 to 24 hours.  After that
 time, Jimena's heading should become west-northwestward as it nears
 a break in this ridge around 140W, created by a mid-level trough
 extending southwestward from California.  A significant decrease in
 forward speed is likely after 96 hours when the cyclone reaches the
 weakness around 140W.  The track guidance is tightly clustered
 through 3 days and is only slightly divergent after that time, with
 the multi-model consensus trending southward during the last 24
 hours from days 3 to 5.  The new track forecast has been nudged
 slightly southward in the short term and a little bit more in the
 extended range, following the trend in the guidance.
 
 The rapid intensification phase that Jimena is undergoing is likely
 to continue in the short term while it encounters relatively light
 shear and moves over anomalously high oceanic heat content. These
 very conducive large-scale factors for intensification suggest that
 Jimena should reach a peak intensity of near category 5 strength in
 about 24 hours or so.  The hurricane could remain around its peak
 intensity through 48 hours, even though SHIPS model output shows
 some drying of the lower to middle troposphere along Jimena's
 track. However, it should be noted that intense hurricanes such as
 Jimena frequently experience eyewall replacements that can cause
 fluctuations in intensity, and their occurrence and evolution are
 nearly impossible to predict. After about 2 days, a slow decay is
 forecast since oceanic and atmospheric conditions will only
 gradually become less conducive.  Jimena's continued strenghtening
 has required an upward adjustment of the intensity forecast in the
 short term, and the new forecast is in excellent agreement with the
 statistical guidance as well as the FSU Superensemble output. The
 new forecast then trends toward the multi-model consensus from days
 3 to 5.
 
 FORECAST POSITIONS AND MAX WINDS
 
 INIT  29/0300Z 12.3N 124.2W  110 KT 125 MPH
  12H  29/1200Z 12.5N 125.5W  125 KT 145 MPH
  24H  30/0000Z 13.0N 127.4W  135 KT 155 MPH
  36H  30/1200Z 13.9N 129.5W  130 KT 150 MPH
  48H  31/0000Z 14.9N 131.9W  125 KT 145 MPH
  72H  01/0000Z 16.3N 136.6W  115 KT 130 MPH
  96H  02/0000Z 17.3N 139.8W  100 KT 115 MPH
 120H  03/0000Z 18.0N 141.7W   85 KT 100 MPH
 
 $$
 Forecaster Kimberlain