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Hurricane DANNY


1100 PM AST FRI AUG 21 2015

After reaching its peak intensity earlier today, Danny appears to
be starting a weakening trend.  There has been no eye in infrared
satellite imagery since about 1800 UTC, and a 2136 UTC WindSat pass
showed that a narrow swath of drier air had worked its way into
the inner core, eroding the southern eyewall.  The shear analysis
from CIMSS at the University of Wisconsin indicates that a little
over 20 kt of southwesterly shear is now affecting Danny, and
dropsonde data from a NOAA G-IV surveillance flight revealed that
there was some light inflow into the western part of the circulation
between 300 and 400 mb.  Dvorak final-T numbers from TAFB and SAB
were steady or decreased slightly from six hours ago; therefore,
the initial intensity is lowered slightly to 95 kt.

Vertical shear is expected to increase further during the next
couple of days, which should allow drier air in the surrounding
environment to penetrate into Danny's circulation.  Therefore,
there is no change in the thinking that Danny should weaken as it
approaches and moves across the Leeward Islands and the Greater
Antilles during the forecast period.  The SHIPS diagnostics is
currently showing only 10 kt of shear affecting Danny, and if the
shear is actually higher as shown by the UW-CIMSS product, then the
SHIPS and LGEM solutions probably keep Danny's intensity too high
during the next few days.  The global models continue to depict
rapid weakening and show Danny degenerating into a surface trough in
3-4 days.  As a compromise, the NHC intensity forecast is close to
the IVCN intensity consensus and a little bit lower than the
previous forecast.  Danny is still expected to weaken to a tropical
storm before it reaches the Leeward Islands between 48-72 hours.

Danny's initial motion remains west-northwestward, or 295/9 kt.
The hurricane is forecast to accelerate and turn westward during
the next few days while the subtropical ridge builds westward over
the southwestern Atlantic.  The bulk of the track guidance is
tightly clustered for the entire forecast period, and no
appreciable changes to the previous NHC track forecast were
required on this advisory cycle.

NOAA and Air Force Reserve Unit reconnaissance aircraft are
scheduled to investigate Danny and the surrounding environment
Saturday afternoon.


INIT  22/0300Z 14.8N  49.8W   95 KT 110 MPH
 12H  22/1200Z 15.1N  51.4W   85 KT 100 MPH
 24H  23/0000Z 15.6N  53.8W   75 KT  85 MPH
 36H  23/1200Z 16.0N  56.4W   65 KT  75 MPH
 48H  24/0000Z 16.4N  59.0W   60 KT  70 MPH
 72H  25/0000Z 17.6N  63.8W   55 KT  65 MPH
 96H  26/0000Z 19.0N  68.5W   45 KT  50 MPH
120H  27/0000Z 20.0N  73.5W   30 KT  35 MPH

Forecaster Berg