000
WTNT45 KNHC 210855
TCDAT5

Tropical Storm Jerry Discussion Number  16
NWS National Hurricane Center Miami FL       AL102019
500 AM AST Sat Sep 21 2019

Data from an Air Force Reserve reconnaissance mission earlier this
morning indicated that Jerry had weakened, with the mid-level
eye/center tilted to the east of the low-level center due to some
westerly mid-level wind shear. The highest 700-mb flight-level and
SFMR surface winds reported were 62 kt and 56 kt, respectively,
which supports a lower intensity of about 55 kt. The minimum
pressure of 995 mb is based on center dropsonde data of 999 mb with
a 38-kt surface wind.

Jerry has turned northwestward and the initial motion estimate is
now 310/13 kt. Jerry is forecast to continue moving northwestward
toward a break in the subtropical ridge today through Sunday,
followed by a northward turn on Monday. By Tuesday, a deep-layer
trough is expected to capture Jerry and accelerate the cyclone
northeastward in the general direction of Bermuda. There remains
excellent agreement among the track models on this developing
scenario, and the official track lies close to the tightly packed
consensus models TVCN, NOAA-HCCA, and FSSE.

Jerry is likely to experience fluctuations in intensity during the
next 72 hours due to increases/decreases in the vertical wind shear
affecting the cyclone. By 96 hours as Jerry moves closer to Bermuda,
the cyclone is forecast to come move into the right-rear entrance
region of a modest jetstream maximum, not unlike what occurred with
former Hurricane Humberto a few days ago. Thus, despite the expected
increase in the vertical wind shear to at least 30 kt,
re-intensification into a hurricane is forecast similar to a
consensus of the global models.

Key Messages:

1. Although the core of Jerry is passing north of the northern
Leeward Islands, heavy rainfall and flash floods are possible there
overnight.


FORECAST POSITIONS AND MAX WINDS

INIT  21/0900Z 21.4N  64.0W   55 KT  65 MPH
 12H  21/1800Z 22.7N  65.4W   55 KT  65 MPH
 24H  22/0600Z 24.3N  66.7W   60 KT  70 MPH
 36H  22/1800Z 26.0N  67.2W   60 KT  70 MPH
 48H  23/0600Z 27.3N  67.4W   55 KT  65 MPH
 72H  24/0600Z 29.8N  66.9W   60 KT  70 MPH
 96H  25/0600Z 33.2N  63.7W   70 KT  80 MPH
120H  26/0600Z 36.7N  60.0W   65 KT  75 MPH

$$
Forecaster Stewart