[Tropical] Tropical Cyclone Discussion

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WTNT42 KNHC 302033
TCDAT2

HURRICANE GASTON DISCUSSION NUMBER  33
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL072016
500 PM AST TUE AUG 30 2016

Gaston appears to have strengthened some more.  The hurricane has
been maintaining a large and well-defined eye with mesovorticies
within it.  In addition, a ring of deep convection surrounds the eye
with little evidence of dry slots.  The Dvorak intensity estimates
have increased from both TAFB and SAB, and they support raising the
initial wind speed a little more to 95 kt. Gaston is likely to
maintain this intensity, or perhaps strengthen a little more, in the
short term while it remains in generally favorable environmental
conditions.  The global models indicate that westerly shear should
increase over Gaston on Wednesday, and that should promote a gradual
weakening trend.  More pronounced weakening is expected when Gaston
moves over cool waters in a couple of days. The NHC intensity
forecast is slightly higher than the previous one at 12 h, based on
the higher initial wind speed, but is otherwise largely unchanged.

The initial motion is now 065/9 kt.  A faster east-northeastward
motion is expected during the next couple of days as the cyclone
becomes more embedded in the mid-latitude westerlies.  A slower
forward speed is forecast beyond a few days when a large
extratropical low nears Gaston and eventually absorbs it in about
5 days. The NHC track forecast is a little slower than the previous
one, and brings a weaker Gaston near the Azores Islands in about
3 days. Interests in that area should monitor the progress of this
system.

The wind radii were modified based on ASCAT and AMSU data from
earlier today.

FORECAST POSITIONS AND MAX WINDS

INIT  30/2100Z 32.6N  51.9W   95 KT 110 MPH
 12H  31/0600Z 33.4N  50.5W   95 KT 110 MPH
 24H  31/1800Z 34.9N  47.6W   90 KT 105 MPH
 36H  01/0600Z 36.6N  43.7W   85 KT 100 MPH
 48H  01/1800Z 37.9N  39.3W   80 KT  90 MPH
 72H  02/1800Z 38.8N  31.5W   60 KT  70 MPH
 96H  03/1800Z 40.0N  26.5W   40 KT  45 MPH
120H  04/1800Z...DISSIPATED

$$
Forecaster Cangialosi

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