000
WTPZ41 KNHC 160834
TCDEP1

TROPICAL STORM ORLENE DISCUSSION NUMBER  22
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP162016
200 AM PDT FRI SEP 16 2016

The satellite presentation of Orlene has continued to deteriorate
during the past six hours.  Cloud-top temperatures have warmed
considerably and several microwave passes show that the remaining
deep convection is limited to the southwest quadrant of the
circulation.  Although CI numbers remain high due to Dvorak
constraints, Data-T numbers from TAFB and SAB continue to fall.  In
the absence of any other data, the initial intensity has been
lowered to 45 kt, based primarily on the substantial degradation of
the cloud pattern and a blend of the subjective Data-T numbers.

Several dynamical models, most notably the GFS, now forecast a more
rapid demise of Orlene than was previously depicted.  In the case of
the GFS, this is probably due to a weaker and more realistic
initialization of the modeled storm at 00 UTC.  The official
forecast therefore shows more rapid weakening than the previous
advisory and is now very close to the multi-model intensity
consensus. Orlene is expected to lose all deep convection and become
post-tropical within 3 days, before dissipating entirely by 120 h.

Orlene has begun to accelerate slightly as expected due to a
strengthening mid-level ridge to the north.  This ridge will
continue to dominate the steering as long as Orlene maintains some
vertical coherence.  A slower forward propagation and slight turn
toward the northwest is expected once Orlene becomes a remnant low.
The official track forecast has been shifted slightly to the north,
mainly because the models depict a shallow remnant low sooner in the
forecast period.  The official forecast remains close to the
GFS/ECMWF consensus.

FORECAST POSITIONS AND MAX WINDS

INIT  16/0900Z 19.9N 125.2W   45 KT  50 MPH
 12H  16/1800Z 19.9N 126.6W   35 KT  40 MPH
 24H  17/0600Z 20.0N 128.8W   30 KT  35 MPH
 36H  17/1800Z 20.0N 131.2W   30 KT  35 MPH
 48H  18/0600Z 20.0N 133.7W   30 KT  35 MPH
 72H  19/0600Z 20.4N 138.7W   25 KT  30 MPH...POST-TROP/REMNT LOW
 96H  20/0600Z 21.5N 142.5W   20 KT  25 MPH...POST-TROP/REMNT LOW
120H  21/0600Z...DISSIPATED

$$
Forecaster Brennan/Zelinsky