359 
 WTPZ41 KNHC 132043
 TCDEP1
 
 HURRICANE ORLENE DISCUSSION NUMBER  12
 NWS NATIONAL HURRICANE CENTER MIAMI FL       EP162016
 200 PM PDT TUE SEP 13 2016
 
 Recent microwave satellite data, including an ASCAT overpass,
 confirm that Orlene has become tilted with the low-level center
 displaced to the south of the weak eye present in visible imagery.
 Based on an average of subjective and objective satellite
 intensity estimates, the initial intensity is reduced to 75 kt.
 
 The microwave data indicate that the center of Orlene is farther
 south than the position on the previous advisory, and the initial
 motion estimate is now 015/2 kt. Orlene is now within a break in
 the subtropical ridge caused a mid- to upper-level trough over
 California and the adjacent waters.  The dynamical models forecast
 the trough to move eastward during the next 24-36 hours, with the
 ridge rebuilding to the north of the tropical cyclone.  This
 evolution should produce a slow motion for the next 12-24 hours,
 followed by a turn toward the west and an increase in forward speed
 during the remainder of the forecast period.  The track guidance is
 in good agreement with this scenario through 96 hours.  After that,
 there remains some spread on whether Orlene will turn more
 northward, as favored by the GFS, or continue westward as favored by
 the ECMWF. The new forecast track is again similar to the previous
 track and lies near the center of the cluster of the consensus and
 dynamical models.
 
 Orlene is experiencing 15-20 kt of southwesterly vertical wind
 shear, and this is likely to continue for about another 24 hours.
 After that time, the dynamical models forecast the shear to decrease
 while the cyclone moves near and parallel to the 26C sea surface
 temperature isotherm.  These conditions, combined with abundant dry
 air seen west of the cyclone in water vapor imagery, should lead to
 gradual weakening through the forecast period.  The new intensity
 forecast is an again an update of the previous forecast, and it lies
 near the upper edge of the envelope of intensity guidance.
 
 FORECAST POSITIONS AND MAX WINDS
 
 INIT  13/2100Z 19.7N 118.7W   75 KT  85 MPH
  12H  14/0600Z 19.9N 118.8W   70 KT  80 MPH
  24H  14/1800Z 20.1N 119.3W   60 KT  70 MPH
  36H  15/0600Z 19.9N 120.9W   55 KT  65 MPH
  48H  15/1800Z 19.7N 122.8W   50 KT  60 MPH
  72H  16/1800Z 19.5N 127.5W   40 KT  45 MPH
  96H  17/1800Z 19.5N 132.5W   40 KT  45 MPH
 120H  18/1800Z 20.0N 136.5W   35 KT  40 MPH
 
 $$
 Forecaster Beven