036 
 WTPZ45 KNHC 072052
 TCDEP5
 
 HURRICANE HILDA DISCUSSION NUMBER   8
 NWS NATIONAL HURRICANE CENTER MIAMI FL       EP102015
 200 PM PDT FRI AUG 07 2015
 
 Hilda has undergone rapid intensification during the past several
 hours, with a small eye forming in the middle of the central dense
 overcast.  The initial intensity, however, is somewhat uncertain due
 to a large spread in the satellite estimates.  Subjective Dvorak
 estimates from TAFB and SAB are 55 kt and 65 kt, while the latest
 AMSU estimates from CIMSS and CIRA are 75 kt and 60 kt.  In
 addition, there is a CIMSS Satellite consensus estimate of about 60
 kt.  Based on these data, the initial intensity is increased to 70
 kt.  The shear observed this morning seems to have diminished, as
 the outflow is increasing in the eastern semicircle.
 
 The initial motion is slightly faster at 275/13.  For the next 48
 hours or so, Hilda should be steered westward to west-northwestward
 by the deep-layer subtropical ridge to its north.  After that time,
 a mid- to upper-level low is expected to develop north of the
 Hawaiian Islands, which should cause Hilda to turn generally
 northwestward.  The track guidance again generally agrees on this
 scenario, and while the GFDL and GFDN models remain right outliers
 there is better overall agreement on how sharply Hilda will turn
 than for the previous forecast.  The new forecast track is nudged a
 little to the west of the previous track based mostly on the
 current position and motion, and it lies near the consensus models
 and the center of the guidance envelope.
 
 It is unclear how long the current rapid intensification will last.
 The Rapid Intensification Index of the SHIPS model shows about a
 30 percent chance of a 25 kt increase in strength during the next
 24 hours.  However, the cloud pattern of the hurricane still has a
 ragged appearance, and due to the small size of the system any
 unfavorable aspect of the environment could stop intensification.
 The new forecast compromises between these extremes and calls for
 continued strengthening at a slower rate through 36 hours.  After
 48-72 hours, the cyclone is expected to encounter strong
 southwesterly vertical shear and decreasing sea surface
 temperatures, and this combination should cause significant
 weakening.  The new intensity forecast remains in best overall
 agreement with the intensity consensus.
 
 
 FORECAST POSITIONS AND MAX WINDS
 
 INIT  07/2100Z 12.7N 138.3W   70 KT  80 MPH
  12H  08/0600Z 13.0N 139.9W   75 KT  85 MPH
  24H  08/1800Z 13.7N 142.0W   80 KT  90 MPH
  36H  09/0600Z 14.4N 144.0W   85 KT 100 MPH
  48H  09/1800Z 15.2N 145.6W   85 KT 100 MPH
  72H  10/1800Z 17.0N 148.5W   75 KT  85 MPH
  96H  11/1800Z 19.0N 150.0W   60 KT  70 MPH
 120H  12/1800Z 20.5N 151.5W   40 KT  45 MPH
 
 $$
 Forecaster Beven