000
WTNT44 KNHC 252038
TCDAT4

Hurricane Lee Discussion Number  31
NWS National Hurricane Center Miami FL       AL142017
500 PM AST Mon Sep 25 2017

Little Lee has weakened a little since the previous advisory. Over
the past few hours, the previously clear 10-15 nmi diameter eye has
become cloud filled, briefly becoming completely obscured. An
average of the available intensity estimates from TAFB, SAB,
UW-CIMSS ADT, UW-CIMSS SATCON, and NHC AODT is 75 kt, and that is
initial intensity used for this advisory.

Lee has completed a tight cyclonic loop and is now moving toward
the west-southwest or 255/07 kt.  A narrow mid-level ridge is
expected to continue building to the north of Lee, forcing the
small hurricane on a westward track for the next day or so. As an
upper-level trough approaches from the west, the hurricane should
turn toward the northwest on Wednesday and Thursday as the western
portion of the subtropical ridge erodes. By Friday and beyond, Lee
is forecast to get caught up in the brisk southwesterly flow ahead
of the aforementioned trough and accelerate toward the northeast at
forward speeds in excess of 20 kt. The official track forecast has
been shifted westward closer to the consensus models through 96 h,
and then lies close to the previous advisory track at 120 h.

The modest southeasterly vertical wind shear that has been affecting
Lee today is forecast by the GFS and ECMWF global models to abate
shortly, and remain at less than 10 kt for the next 48 hours or so.
As a result, some slight strengthening will be possible when the
cyclone moves over warmer 28 deg C SSTs in 36-48 hours. Afterwards,
increasing southwesterly vertical shear should induce slow but
steady weakening, with Lee making the transition into an
extratropical low by 120 h when the cyclone will be located over
18C-20C water temperatures and in a 30-40 kt sheared environment.

Lee is forecast to remain a compact hurricane throughout the
forecast period, with only a small increase in the 50- and
34-kt wind radii expected.

FORECAST POSITIONS AND MAX WINDS

INIT  25/2100Z 30.5N  50.6W   75 KT  85 MPH
 12H  26/0600Z 30.4N  51.6W   75 KT  85 MPH
 24H  26/1800Z 30.5N  53.4W   75 KT  85 MPH
 36H  27/0600Z 31.0N  55.0W   80 KT  90 MPH
 48H  27/1800Z 31.8N  55.6W   80 KT  90 MPH
 72H  28/1800Z 34.5N  54.3W   75 KT  85 MPH
 96H  29/1800Z 40.2N  47.5W   60 KT  70 MPH
120H  30/1800Z 46.9N  35.0W   50 KT  60 MPH...POST-TROP/EXTRATROP

$$
Forecaster Stewart