000
WTNT45 KNHC 220239
TCDAT5

Tropical Storm Jerry Discussion Number  19
NWS National Hurricane Center Miami FL       AL102019
1100 PM AST Sat Sep 21 2019

Jerry's center is still exposed to the northwest of the bulk of the
deep convection, although a new burst of thunderstorms is just now
developing just to the southeast of the center.  With no
significant change to the storm's structure, the initial intensity
is held at 55 kt, which matches a blend of final-T and CI numbers
from TAFB and SAB.  UW-CIMSS is depicting 15-20 kt of westerly
shear over Jerry at the moment, although the analysis suggests that
the cyclone could sneak into a slightly lower-shear environment
during the next 12-24 hours.  After that time, however, Jerry is
expected to interact with a mid- to upper-level trough, putting the
system under counterbalancing influences of strong shear but
stronger divergence aloft.  Because of these conditions, only small
fluctuations in intensity are expected during the next 4 days or
so.  Jerry will be bumping up against a baroclinic zone while
interacting with the trough, and it's likely that extratropical
transition will at least commence while this system is over the
western Atlantic.  At this point, however, that transition is not
expected to be complete before the end of the 5-day forecast period.

The initial motion is northwestward, or 325/13 kt.  Jerry is still
expected to continue recurving around the subtropical ridge,
interact with the western Atlantic trough in about 48 hours, and
then become embedded in the mid-latitude westerlies from day 3
onward.  Except for a slight westward kink in the track between
48-72, resulting from Jerry's expected interaction with the trough,
little change in the NHC track forecast was required from the
previous one.


Key Messages:

1. The risk of tropical-storm-force winds on Bermuda is increasing,
with Jerry forecast to pass near the island Tuesday and Wednesday.
It is too soon to determine what impacts the system may have on
Bermuda, but interests there should monitor the progress of Jerry.


FORECAST POSITIONS AND MAX WINDS

INIT  22/0300Z 24.1N  66.3W   55 KT  65 MPH
 12H  22/1200Z 25.4N  67.1W   55 KT  65 MPH
 24H  23/0000Z 26.7N  67.8W   60 KT  70 MPH
 36H  23/1200Z 28.0N  68.0W   60 KT  70 MPH
 48H  24/0000Z 29.4N  68.0W   60 KT  70 MPH
 72H  25/0000Z 32.6N  66.2W   55 KT  65 MPH
 96H  26/0000Z 36.8N  60.2W   55 KT  65 MPH
120H  27/0000Z 40.8N  54.0W   50 KT  60 MPH

$$
Forecaster Berg