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Subtropical Storm Leslie Discussion Number   4
NWS National Hurricane Center Miami FL       AL132018
500 AM AST Mon Sep 24 2018

Leslie has changed little overnight.  The large subtropical cyclone
continues to produce patches of deep convection, mostly to the south
and east of the center.  The initial intensity is again held at 35
kt, which is near the upper end of the satellite intensity
estimates.

The subtropical storm is moving southward at 5 kt.  The steering
currents around Leslie are expected to collapse later today and
little overall motion is forecast during the next 12-18 hours.
After that time, a cold front is expected to approach the system,
and that should cause Leslie to move eastward tonight and Tuesday.
The front is expected to merge with Leslie by Tuesday night, causing
it to become extratropical.  While little change in intensity is
expected during the next day or so, due to dry air and moderate
shear, some strengthening as an extratropical low is likely due to
baroclinic forcing.  In fact, after becoming extratropical, the
models show Leslie merging with another frontal low to its north,
leading to the formation of a powerful slow-moving non-tropical low
with gale- or storm-force winds over the central Atlantic later this
week.

FORECAST POSITIONS AND MAX WINDS

INIT  24/0900Z 32.6N  48.6W   35 KT  40 MPH
 12H  24/1800Z 32.6N  48.3W   35 KT  40 MPH
 24H  25/0600Z 32.6N  46.9W   35 KT  40 MPH
 36H  25/1800Z 32.5N  44.8W   35 KT  40 MPH
 48H  26/0600Z 32.7N  42.0W   45 KT  50 MPH...POST-TROP/EXTRATROP
 72H  27/0600Z...MERGED WITH FRONTAL SYSTEM

$$
Forecaster Cangialosi

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