000
WTPZ43 KNHC 261442
TCDEP3

TROPICAL STORM ROSLYN DISCUSSION NUMBER   5
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP182016
800 AM PDT MON SEP 26 2016

Roslyn remains a large, but sheared tropical storm.  An 0847 UTC
AMSR microwave overpass indicates that the low-level center is
located well to west of the large area of deep convection, due to
moderate southwesterly shear.  Dvorak intensity estimates from
TAFB and SAB are unchanged from before, so the initial intensity
is kept at 35 kt for this advisory.  The southwesterly shear that
is currently affecting the cyclone is predicted to increase during
the next 24 hours, which should prevent significant strengthening
while Roslyn remains over marginally warm water.  In a little
more than 24 hours, the tropical storm will be crossing the 26 deg C
isotherm and moving into a more stable air mass, which should begin
the weakening process.  The NHC forecast shows Roslyn becoming a
remnant low within 48 hours, and dissipating by the end of the
forecast period.

Recent fixes suggest that Roslyn is moving north-northeastward
or 015/4 kt.  The tropical storm should turn northeastward today in
the southwesterly flow between a mid-level ridge to the southeast
and a large mid- to upper-level low over the Baja California
peninsula.  After Roslyn weakens into a shallow remnant low, it
should turn northward and then northwestward in the low-level flow
west of the Baja peninsula.  The new NHC track forecast is very
similar to the previous advisory, and is a blend of the GFS, ECMWF,
and GFS ensemble mean.


FORECAST POSITIONS AND MAX WINDS

INIT  26/1500Z 17.0N 119.4W   35 KT  40 MPH
 12H  27/0000Z 17.5N 119.0W   35 KT  40 MPH
 24H  27/1200Z 18.5N 118.1W   35 KT  40 MPH
 36H  28/0000Z 19.7N 117.3W   30 KT  35 MPH
 48H  28/1200Z 21.0N 117.2W   25 KT  30 MPH...POST-TROP/REMNT LOW
 72H  29/1200Z 23.2N 118.1W   20 KT  25 MPH...POST-TROP/REMNT LOW
 96H  30/1200Z 24.5N 119.7W   20 KT  25 MPH...POST-TROP/REMNT LOW
120H  01/1200Z...DISSIPATED

$$
Forecaster Brown