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Tropical Storm Leslie Discussion Number 23
NWS National Hurricane Center Miami FL AL132018
1100 PM AST Mon Oct 01 2018
Satellite imagery shows that the convective organization of Leslie
has changed little during the past several hours. The eye-like
feature, however, has become a little more distinct and symmetric.
The subjective and objective intensity estimates haven't changed
though, and the initial intensity remains at 50 kt for this
The initial motion is estimated to be a southwestward drift, or
220/4 kt. Leslie is forecast to continue drifting generally
southwestward through the 36-hour period in relatively weak
mid-tropospheric steering flow produced by a ridge extending
eastward from the southeast United States to near Bermuda.
Afterwards, an amplifying mid-latitude shortwave trough approaching
the cyclone from the Canadian Maritimes should induce a
north-northeastward to northeastward motion at an increasing forward
speed. The NHC forecast is adjusted just to the left of the
previous forecast track beyond 36 hours to align more with the TVCN
The intensity forecast philosophy remains basically the same, this
evening. Strengthening is still expected during the next 36 hours
and Leslie is likely to become a hurricane Tuesday tonight, as
indicated by the statistical and multi-model intensity guidance.
Near the 72-hour period, Leslie should begin a gradual weakening
trend as the cyclone moves back over cooler oceanic temperatures
and some invading drier mid-level air, associated with the
aforementioned shortwave trough which stabilizes the surrounding
environment. The official intensity forecast is an update of the
previous one and is close to the IVCN and NOAA-HCCA consensus aids.
The forecast wind radii have been adjusted based on the RVCN
(GFS/ECMWF/HWRF) multi-model consensus.
Large swells generated by Leslie will continue to affect portions of
the southeastern coast of the United States, Bermuda, and the
Bahamas. These swells could cause life-threatening surf and
rip currents. Although the swells are forecast to abate temporarily
in the Bahamas Tuesday, they are expected to increase again
Wednesday and Thursday and propagate farther southward into the
Greater and Lesser Antilles. Please consult products from your
local weather office.
FORECAST POSITIONS AND MAX WINDS
INIT 02/0300Z 32.4N 55.0W 50 KT 60 MPH
12H 02/1200Z 31.3N 55.7W 55 KT 65 MPH
24H 03/0000Z 30.2N 56.3W 65 KT 75 MPH
36H 03/1200Z 29.9N 56.6W 70 KT 80 MPH
48H 04/0000Z 30.6N 56.4W 70 KT 80 MPH
72H 05/0000Z 34.4N 55.9W 65 KT 75 MPH
96H 06/0000Z 37.0N 55.0W 60 KT 70 MPH
120H 07/0000Z 37.3N 52.5W 55 KT 65 MPH