Hurricane GONZALO

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HURRICANE GONZALO DISCUSSION NUMBER  12
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL082014
500 AM AST WED OCT 15 2014

The small eye of Gonzalo has become a little less distinct in
infrared satellite imagery overnight.  It is possible that an eye
wall replacement has begun, but there has been no recent microwave
images to assess the current structure of the inner core.  There
has been little change in the subjective and objective Dvorak
satellite intensity estimates overnight and the initial wind speed
remains 110 kt for this advisory.  Another Air Force Reserve
reconnaissance aircraft is en route to the hurricane, which should
provide a better assessment of the intensity of Gonzalo this
morning.

A UW/CIMSS shear analysis and the SHIPS model indicate that there is
still some light to moderate southerly shear over the hurricane, but
the shear is expected to decrease today.  This favors
intensification, however difficult-to-predict eye wall replacement
cycles could cause some fluctuations in intensity during the next
day or two.  The NHC forecast calls for some slight intensification
today followed by little change in strength in 24 to 48 hours.
After that time, increasing southwesterly shear, drier air, and
cooler sea surface temperatures should cause weakening.  Gonzalo is
expected to become extratropical by day 4, and the global models
indicate that it will remain a powerful extratropical low through
the end of the forecast period.

Gonzalo is moving northwestward or 320/11 kt.  The forecast track
reasoning remains unchanged.  The hurricane should turn north-
northwestward and northward during the next day or so as it moves
around the western side of a mid-level ridge over the central
Atlantic.  After that time, Gonzalo is forecast to turn
north-northeastward and accelerate ahead of a mid-latitude trough
that will be moving off the east coast of the United States.  The
track guidance is in excellent agreement on this scenario, however
the updated NHC forecast has been shifted a little west of
the previous advisory to be closer to the middle of the guidance
envelope.

FORECAST POSITIONS AND MAX WINDS

INIT  15/0900Z 22.9N  67.3W  110 KT 125 MPH
 12H  15/1800Z 24.0N  68.3W  115 KT 130 MPH
 24H  16/0600Z 25.5N  68.9W  115 KT 130 MPH
 36H  16/1800Z 27.3N  68.5W  110 KT 125 MPH
 48H  17/0600Z 29.9N  67.1W  105 KT 120 MPH
 72H  18/0600Z 37.5N  62.8W   90 KT 105 MPH
 96H  19/0600Z 48.5N  52.5W   70 KT  80 MPH...POST-TROP/EXTRATROP
120H  20/0600Z 54.0N  30.0W   55 KT  65 MPH...POST-TROP/EXTRATROP

$$
Forecaster Brown

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