000
WTNT43 KNHC 060849
TCDAT3

Tropical Storm Leslie Discussion Number  40
NWS National Hurricane Center Miami FL       AL132018
500 AM AST Sat Oct 06 2018

Leslie is producing a cluster of deep convection near its center of
circulation and a far-reaching band that curls around the eastern
side of the expansive circulation.  The maximum winds are still
estimated to be 50 kt based on last evening's ASCAT pass.  Leslie's
future intensity will largely be limited by a less-than-ideal
thermodynamic environment, with the center moving over water
temperatures of 24-25 degrees Celsius within its own cold wake
during the next 48 hours.  Some weakening is anticipated during that
period, and the NHC forecast follows the intensity consensus and
HCCA guidance.  After 48 hours, some restrengthening is possible
when Leslie reaches some warmer waters, although increasing
westerly shear is likely to temper the amount of intensification.

Leslie's current motion is northeastward, or 045/7 kt.  The cyclone
is becoming increasingly embedded within the mid-latitude
westerlies, and these winds, with the assistance of a couple of
shortwave troughs, are expected to push Leslie toward the east and
southeast throughout the forecast period.  The one notable model
anomaly is the ECMWF, which shows Leslie becoming more separated
from the mid-latitude flow and moving more slowly than shown in the
other models on days 3 through 5.  Even with that model being an
outlier, the rest of the guidance has sped up a bit, pulling the
consensus aids eastward.  This resulted in the new NHC track
forecast being a little faster than the previous one on days 4 and
5.

Large swells generated by Leslie are expected to continue during the
next few days across the eastern coast of the United States,
Bermuda, the Bahamas, the Greater and Lesser Antilles, and Atlantic
Canada.  Please consult products from your local weather office as
these conditions could cause life-threatening surf and rip currents.


FORECAST POSITIONS AND MAX WINDS

INIT  06/0900Z 37.2N  56.4W   50 KT  60 MPH
 12H  06/1800Z 37.3N  55.0W   50 KT  60 MPH
 24H  07/0600Z 37.1N  52.6W   50 KT  60 MPH
 36H  07/1800Z 36.5N  50.2W   45 KT  50 MPH
 48H  08/0600Z 35.7N  47.8W   40 KT  45 MPH
 72H  09/0600Z 33.4N  42.6W   45 KT  50 MPH
 96H  10/0600Z 30.5N  37.5W   50 KT  60 MPH
120H  11/0600Z 28.5N  32.5W   50 KT  60 MPH

$$
Forecaster Berg