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HURRICANE GASTON DISCUSSION NUMBER  22
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL072016
1100 PM AST SAT AUG 27 2016

Gaston has become a hurricane again with a well-defined eye on
microwave images that has been occasionally showing up on
conventional satellite pictures.  Dvorak estimates are T4.5/77 kt
from both TAFB and SAB, so the initial wind speed is increased to 75
kt. The environment near Gaston, other than some dry mid-level air,
looks conducive for strengthening for the next day or so.  While
the environment doesn't change much in the next couple of days
overall, Gaston is expected to move very slowly, which could upwell
some cooler water.  Thus the wind speed forecast will be leveled
off after 24 hours.  A more consistent weakening trend is expected
beyond 72 hours when the cyclone moves over colder waters and
experiences stronger shear.  The latest NHC prediction is higher
than the previous one, mostly owing to the initial conditions, and
is close to a blend of the FSU Superensemble and the intensity
consensus.

Satellite fixes show that Gaston is moving slower to the northwest,
at about 7 kt.  The storm should continue to decelerate over the
next day or so as it reaches a break in the subtropical ridge, and
have a slow motion to the north or northeast from 24 to 48 hours.
The next shortwave trough in the mid-latitude is forecast to reach
Gaston in about 3 days, which will likely cause the hurricane to
recurve to the east-northeast, albeit at a slower rate of speed than
you normally see over the North Atlantic.  Guidance has not changed
much since the last cycle, and the official forecast is basically an
update of the previous one, a bit slower than the model consensus.


FORECAST POSITIONS AND MAX WINDS

INIT  28/0300Z 29.6N  54.2W   75 KT  85 MPH
 12H  28/1200Z 30.1N  54.7W   85 KT 100 MPH
 24H  29/0000Z 30.7N  55.1W   95 KT 110 MPH
 36H  29/1200Z 31.0N  55.2W   95 KT 110 MPH
 48H  30/0000Z 31.4N  54.8W   90 KT 105 MPH
 72H  31/0000Z 32.6N  52.2W   90 KT 105 MPH
 96H  01/0000Z 34.6N  48.1W   85 KT 100 MPH
120H  02/0000Z 37.5N  42.0W   70 KT  80 MPH

$$
Forecaster Blake

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