Official Discussion issued by the National Hurricane Center

Leslie (AL132018) DATA RELEASED: 9/30/2018 5:00:00 AM UTC

Copy of official data

Tropical Storm Leslie Discussion Number  16
NWS National Hurricane Center Miami FL       AL132018
500 AM AST Sun Sep 30 2018

Convection associated with the tropical storm has become more
fragmented over the past 12 hours or so, and now consists of several
broken bands primarily over the southeastern portion of the
circulation.  Satellite intensity estimates have not changed much
since the previous advisory, and the initial intensity is held at
45 kt, which is in agreement with earlier ASCAT data and a recent
UW/CIMSS SATCON estimate of 42 kt.  The recent warming of the clouds
tops may be associated with cooler waters caused by upwelling
beneath the large, slow-moving tropical storm.  Leslie, however is
forecast to move southwestward toward somewhat warmer waters and a
more favorable upper-level environment during the next 2 to 3 days.
This conditions should allow for gradual strengthening, and the NHC
forecast follows the intensity guidance by bringing Leslie to
hurricane strength in about 72 hours.  Later in the period, Leslie
is likely to move back over some of the cooler upwelled waters along
its previous track, which could result in gradual weakening.

Recent satellite fixes show that Leslie is moving west-
southwestward or 240 degrees at 4 kt. The tropical storm is caught
between a pair of mid-level ridges and a slow southwestward to
south-southwestward motion is expected over the next 2 to 3 days.
Around mid-week, a shortwave trough moving off the coast of the
northeastern United States is expected to help lift Leslie slowly
northward at days 4 and 5, but the models have trended toward a
somewhat slower solution.  Despite the storm's expected slow motion,
the spread in the track guidance becomes fairly large by days 4 and
5, and it appears that Leslie is likely to meander over the Central
Atlantic for quite some time.

Large swells generated by Leslie when it was a strong extratropical
low will affect Bermuda, the east coast of the United States, and
most of the Greater and Lesser Antilles through at least the early
part of this week.  These swells could cause life-threatening surf
and rip currents.

FORECAST POSITIONS AND MAX WINDS

INIT  30/0900Z 33.8N  52.5W   45 KT  50 MPH
12H  30/1800Z 33.4N  53.2W   45 KT  50 MPH
24H  01/0600Z 32.9N  53.8W   50 KT  60 MPH
36H  01/1800Z 32.5N  54.2W   55 KT  65 MPH
48H  02/0600Z 31.9N  54.5W   55 KT  65 MPH
72H  03/0600Z 30.7N  54.7W   65 KT  75 MPH
96H  04/0600Z 32.4N  54.1W   65 KT  75 MPH
120H  05/0600Z 35.5N  53.0W   60 KT  70 MPH

$$
Forecaster Brown