490 
 WTPZ43 KNHC 300251
 TCDEP3
 
 HURRICANE JIMENA DISCUSSION NUMBER  14
 NWS NATIONAL HURRICANE CENTER MIAMI FL       EP132015
 800 PM PDT SAT AUG 29 2015
 
 Jimena continues to undergo an eyewall replacement, with significant
 inner-core structural changes seen in satellite data throughout
 the day.  Microwave images show a small inner eyewall rotating
 around an irregularly-shaped outer eyewall at about 60 n mi radius,
 the latter which could be slowly contracting.  Although Jimena's
 cloud pattern has fluctuated some during this period of inner-core
 change, its overall organization has remained about the same
 since the last advisory.  Satellite classifications seem to bear
 this out, with intensity estimates of T6.0/115 kt and T6.5/127 kt
 from SAB and TAFB, respectively, at 0000 UTC.  These are blended
 with the latest UW-CIMSS ADT value of 6.1/117 kt to keep the initial
 intensity estimate at 120 kt.
 
 The intensity forecast is challenging.  The large-scale environment
 is forecast to remain relatively favorable during the next day or
 two, apart from some north-northwesterly shear associated with a
 cold low to the northeast of Jimena.  This could allow an
 opportunity for reintensification if the current eyewall
 replacement fully plays out, but predicting intensity fluctuations
 due to inner-core dynamics is nearly impossible and beyond the
 scope of this forecast. Thus, a slow decrease in intensity is
 indicated in the new forecast as large-scale conditions only
 gradually become less conducive.  This is a blend of the
 statistical-dynamical guidance. As Jimena gradually gains latitude
 later in the forecast period, global models show a minor increase in
 westerly shear while other thermodynamic factor remain generally
 neutral, except for slowly decreasing SSTs.  These factors suggests
 a slow decay of the cyclone, and the new intensity forecast is in
 agreement with the latest multi-model consensus that shows a
 monotonic decrease in intensity from days 3 to 5.
 
 The eye of Jimena has been wobbling quite a bit, but smoothing
 through these yields a faster initial motion estimate of 295/11.
 Jimena should continue moving west-northwestward during the next few
 days as it approaches the western end of a subtropical ridge around
 140W.  A weakness in the ridge around this longitude should induce a
 significant deceleration by days 4 and 5.  The track guidance is in
 excellent agreement through the first 2 days, with less-than-typical
 spread beyond that time.  The new track forecast is faster and
 adjusted slightly southward and then westward after day 3, but not
 as far south or west as the multi-model consensus.
 
 
 FORECAST POSITIONS AND MAX WINDS
 
 INIT  30/0300Z 13.3N 127.5W  120 KT 140 MPH
  12H  30/1200Z 13.9N 129.3W  115 KT 130 MPH
  24H  31/0000Z 14.7N 131.8W  110 KT 125 MPH
  36H  31/1200Z 15.4N 134.4W  110 KT 125 MPH
  48H  01/0000Z 16.0N 136.7W  105 KT 120 MPH
  72H  02/0000Z 16.9N 139.9W   95 KT 110 MPH
  96H  03/0000Z 17.6N 141.9W   85 KT 100 MPH
 120H  04/0000Z 18.1N 143.4W   75 KT  85 MPH
 
 $$
 Forecaster Kimberlain