466 
 WTPZ43 KNHC 291434
 TCDEP3
 
 HURRICANE JIMENA DISCUSSION NUMBER  12
 NWS NATIONAL HURRICANE CENTER MIAMI FL       EP132015
 800 AM PDT SAT AUG 29 2015
 
 Convective cloud tops in the central dense overcast have warmed
 since the last advisory, but the 10-15 n mi wide eye remains
 distinct.  An 0913 UTC GCOM overpass clearly indicated that the
 formation of a secondary outer eyewall was almost complete, which
 could be a harbinger that Jimena will soon go through an eyewall
 replacement.  Dvorak Current Intensity estimates at 1200 UTC were
 6.0/115 kt from TAFB, 6.5/127 kt from SAB, and 6.8/135 kt from the
 CIMSS ADT, and the initial intensity is held at 130 kt.
 
 This advisory continues to show the possibility of Jimena reaching
 category 5 intensity during the next 24 hours since the environment
 remains conducive for strengthening.  However, if Jimena does go
 through an eyewall replacement soon, then fluctuations in intensity
 are likely to occur, and the hurricane could actually weaken a bit
 in the short term.  The intensity forecast is somewhat challenging
 after 24 hours.  Vertical shear is expected to remain low, and sea
 surface temperatures remain above 26C through the forecast period,
 but the hurricane models show a general decay to a category 1 or 2
 cyclone by day 5.  On the other hand, the global models,
 particularly the GFS and ECMWF, seem to take more advantage of the
 favorable environment and retain central pressures that would
 support a category 3 or 4 hurricane through day 5.  Therefore, the
 NHC intensity forecast shows a much slower decay than indicated by
 the hurricane models, keeping Jimena as a major hurricane through
 day 4.
 
 Jimena's eye has been wobbling around, but the longer-term motion
 estimate is 275/7 kt.  The ridge to the north of the hurricane
 appears to be weakening, and Jimena is expected to turn
 west-northwestward later today.  This trajectory should continue
 through day 5, with a decrease in forward speed by days 4 and 5
 when the steering currents become much weaker.  The track guidance
 is still in good agreement on the future track, and the updated NHC
 forecast is similar to, but slightly faster than, the previous
 forecast after 24 hours.
 
 FORECAST POSITIONS AND MAX WINDS
 
 INIT  29/1500Z 12.5N 125.6W  130 KT 150 MPH
  12H  30/0000Z 13.0N 127.0W  135 KT 155 MPH
  24H  30/1200Z 13.9N 129.1W  140 KT 160 MPH
  36H  31/0000Z 14.7N 131.5W  135 KT 155 MPH
  48H  31/1200Z 15.4N 133.9W  130 KT 150 MPH
  72H  01/1200Z 16.5N 137.9W  115 KT 130 MPH
  96H  02/1200Z 17.1N 140.5W  100 KT 115 MPH
 120H  03/1200Z 17.6N 142.1W   90 KT 105 MPH
 
 $$
 Forecaster Berg