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Tropical Storm Lee Discussion Number 48
NWS National Hurricane Center Miami FL AL142017
1100 PM AST Fri Sep 29 2017
Lee has been devoid of deep convection for the past 6 hours due to
strong northwesterly vertical wind shear and sea-surface
temperatures near 20 deg C. The initial intensity has been lowered
to 50 kt based on a UW-CIMSS ADT intensity estimate of 51 kt and
typical decay rate for tropical cyclones at that latitude. Lee is
forecast to become an extratropical low in the next 6-12 h due to
aforementioned strong shear and cold ocean temperatures. However,
due to a continued increase in forward speed, little change in
strength is expected until dissipation occurs in 12-24 hours
despite the lack of any significant convection with the system.
Lee has continued to accelerate toward the northeast, and the
initial motion estimate is now 060/36 kt. For the next day or so,
Lee will remain embedded within deep-layer southwesterly flow ahead
of a mid-/upper-level trough, and continue to accelerate toward the
northeast. Since the models remain tightly clustered, no change was
made to the previous forecast track.
FORECAST POSITIONS AND MAX WINDS
INIT 30/0300Z 44.3N 42.8W 50 KT 60 MPH
12H 30/1200Z 47.8N 33.0W 50 KT 60 MPH...POST-TROP/EXTRATROP
24H 01/0000Z...DISSIPATED
$$
Forecaster Stewart
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