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Tropical Depression Lee Discussion Number 15
NWS National Hurricane Center Miami FL AL142017
1100 AM AST Mon Sep 18 2017
After being nearly devoid of thunderstorm activity overnight, a
burst of deep convection has developed near and to the east of
the center this morning. The initial intensity is held at 30 kt,
in agreement with earlier ASCAT data. Despite the development of
deep convection, the overall forecast reasoning for Lee's future
intensity is unchanged. Lee is expected to be embedded within very
strong westerly to northwesterly shear during the next couple of
days. These hostile winds, combined with a dry environment, should
cause Lee to weaken and become a remnant low in about 24 hours.
The global models suggest that Lee could open up into a trough
within the next 2 to 3 days. Since the models remain in good
agreement, and the NHC intensity forecast is basically the same as
the previous one.
Lee is moving west-northwestward at 12 kt on the southwest side of
a mid-level high pressure system. A turn to the northwest with a
decrease in forward speed is expected by tonight as the tropical
depression moves toward a large-scale trough. A continued
northwestward motion is forecast until the system dissipates over
the central Atlantic. There is not much spread in the model
solutions, and the NHC track forecast lies near the middle of the
guidance envelope.
FORECAST POSITIONS AND MAX WINDS
INIT 18/1500Z 14.1N 40.6W 30 KT 35 MPH
12H 19/0000Z 14.8N 41.9W 30 KT 35 MPH
24H 19/1200Z 16.0N 43.2W 25 KT 30 MPH...POST-TROP/REMNT LOW
36H 20/0000Z 17.4N 44.2W 25 KT 30 MPH...POST-TROP/REMNT LOW
48H 20/1200Z 18.9N 45.3W 20 KT 25 MPH...POST-TROP/REMNT LOW
72H 21/1200Z...DISSIPATED
$$
Forecaster Cangialosi
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