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HURRICANE ORLENE DISCUSSION NUMBER  11
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP162016
800 AM PDT TUE SEP 13 2016

Orlene has become less organized during the past several hours.
The eye has disappeared in infrared satellite imagery, and a recent
microwave overpass suggests that the cyclone is now tilted toward
the north-northeast.  Based on an average of satellite intensity
estimates from SAB, TAFB, and the CIMSS satellite consensus, the
initial intensity is reduced to 85 kt, and this could be a little
generous.

The initial motion is 015/4.  Orlene is currently moving into 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 24-48 hours,
with the ridge rebuilding to the north of the tropical cyclone.
This evolution should produce a slow motion for the next day or so,
followed by a turn toward the west and an increase in forward speed
during most of the balance of the forecast period.  The track
guidance is in good agreement with this scenario through 96 hours,
with some divergence at 120 hours on whether Orlene will turn more
northward or continue westward.  The new forecast track is similar
to the previous track and lies near the center of the cluster of
consensus and dynamical models.

Orlene is experiencing about 15 kt of southwesterly vertical wind
shear, and this is likely to continue for another 24 hours or so.
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 microwave imagery,
should lead to gradual weakening through the forecast period.  The
new intensity forecast is an update of the previous forecast and is
in good agreement with the SHIPS and LGEM models.

FORECAST POSITIONS AND MAX WINDS

INIT  13/1500Z 19.8N 118.7W   85 KT 100 MPH
 12H  14/0000Z 20.2N 118.8W   75 KT  85 MPH
 24H  14/1200Z 20.3N 119.1W   65 KT  75 MPH
 36H  15/0000Z 20.4N 120.1W   55 KT  65 MPH
 48H  15/1200Z 20.3N 121.8W   50 KT  60 MPH
 72H  16/1200Z 20.0N 126.5W   45 KT  50 MPH
 96H  17/1200Z 20.0N 131.5W   40 KT  45 MPH
120H  18/1200Z 20.5N 135.5W   35 KT  40 MPH

$$
Forecaster Beven

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