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Hurricane Lee Discussion Number  38
NWS National Hurricane Center Miami FL       AL142017
1100 AM AST Wed Sep 27 2017

After an eyewall replacement overnight, satellite images indicate
that a larger clear eye has formed, with the coldest cloud-top
temperatures seen to date observed with the cyclone.  While
subjective Dvorak estimates have been fluctuating between 90-102 kt,
the latest objective estimate is 102 kt, and a 1050 UTC AMSU
estimate from CIMSS is 104 kt.  A blend of these data gives an
initial wind speed of 100 kt, making Lee the 5th major hurricane of
the 2017 Atlantic season.  A gradual decrease in water temperatures
should start a weakening trend within 12-24 hours, with a faster
weakening forecast on Thursday and Friday as Lee enters a high-shear
environment.  Guidance is in good agreement on this scenario, and
the latest forecast is very close to the previous one.

Lee has turned northwestward, or 315/6.  The hurricane should turn
to the north on Thursday and northeast by Friday while it moves
around the subtropical ridge.  Lee is expected to move quite quickly
to the northeast on Friday and Saturday as it accelerates in
mid-latitude flow.  No significant changes were made to the previous
track, and the new forecast lies between the ECMWF and the HFIP
corrected-consensus model.  Around day 3, the cyclone should be
close to a cold front, but most of the models still show it separate
from that feature.  By day 4, all of the guidance have the system
decaying into a trough, and that is the solution provided below.

An ASCAT pass from this morning indicated that Lee has grown in
size, so the initial and forecast wind radii have been modified to
reflect that change.


FORECAST POSITIONS AND MAX WINDS

INIT  27/1500Z 30.6N  56.8W  100 KT 115 MPH
 12H  28/0000Z 31.4N  57.3W   95 KT 110 MPH
 24H  28/1200Z 33.0N  57.2W   90 KT 105 MPH
 36H  29/0000Z 35.5N  55.5W   80 KT  90 MPH
 48H  29/1200Z 39.0N  51.5W   70 KT  80 MPH
 72H  30/1200Z 46.5N  34.5W   55 KT  65 MPH
 96H  01/1200Z...DISSIPATED

$$
Forecaster Blake

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