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TROPICAL STORM DANNY DISCUSSION NUMBER   8
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL042015
500 AM AST THU AUG 20 2015

The cloud pattern resembles a tropical cyclone much more than 12
hours ago.  An irregular Central Dense Overcast(CDO) has formed, and
the center continues to be remarkably well depicted in microwave
images. In fact, it has a much better structure than earlier. The
outflow remains fair. Dvorak numbers suggest that the winds are
still 45 kt. Danny has the opportunity to strengthen a little during
the next 2 to 3 days while embedded within very light shear. Models
in general, however, no longer intensify the cyclone as much as they
did in earlier runs and, in fact, the GFS and ECMWF weaken Danny to
a tropical wave in the eastern Caribbean Sea. The NHC forecast calls
for some intensification for the next 3 days, and calls for slight
weakening as Danny encounters high shear and dry air in the eastern
Caribbean Sea.

Microwave fixes indicate that Danny is moving toward the west or 280
degrees at 9 kt. A turn toward the west-northwest toward a weakness
in the subtropical ridge is expected soon. After 48 hours, most
of the global models forecast the subtropical ridge to expand
westward, forcing Danny to turn back to the west as indicated in the
NHC forecast.  The multi-model consensus as well as the consensus of
the GFS and the ECMWF depict the expansion of the ridge, and bring
Danny to the eastern Caribbean, while the UK and the GFDL models
insist on taking the cyclone north of the islands. In summary, it
appears that a tropical cyclone or a perhaps a wave will be moving
over the Leeward Islands between 4 and 5 days.


FORECAST POSITIONS AND MAX WINDS

INIT  20/0900Z 12.2N  43.7W   45 KT  50 MPH
 12H  20/1800Z 12.6N  44.9W   50 KT  60 MPH
 24H  21/0600Z 13.5N  46.3W   55 KT  65 MPH
 36H  21/1800Z 14.3N  47.8W   60 KT  70 MPH
 48H  22/0600Z 15.0N  50.0W   65 KT  75 MPH
 72H  23/0600Z 15.5N  54.4W   65 KT  75 MPH
 96H  24/0600Z 16.3N  60.0W   65 KT  75 MPH
120H  25/0600Z 17.0N  65.0W   50 KT  60 MPH

$$
Forecaster Avila

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