Tropical Cyclone Discussion
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000
WTPZ44 KNHC 300235
TCDEP4

TROPICAL DEPRESSION NINE-E DISCUSSION NUMBER   1
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP092015
800 PM PDT WED JUL 29 2015

Satellite imagery and reports from NOAA buoy 51307 indicate that
the large low pressure area well southwest of the southern tip of
the Baja California has a closed circulation and sufficient
convection to be considered a tropical depression.  Thus, advisories
are being initiated on Tropical Depression Nine-E.  The initial
intensity is set at 30 kt, which could be conservative given the
current convective organization.

The initial motion is 280/13.  For the next three days or so, a
strong low- to mid-level ridge north of the cyclone should steer it
generally west-northwestward, and the forecast track is in the
center of the guidance envelope during this period.  From 72-120
hours, the dynamical models suggest a mid- to upper-level trough
should weaken the ridge to the northeast of the Hawaiian Islands.
The guidance becomes somewhat divergent during this time, with the
GFS and ECMWF models showing a more northward motion, while the
Canadian, UKMET, HWRF, and NAVGEM models show a continued
west-northwestward motion.  The track forecast follows the GFS/ECMWF
solutions in calling for a turn toward the northwest and a decrease
in forward speed.

The depression is over warm sea surface temperatures and is expected
to remain in a moist environment with light vertical wind shear for
the next 72 hours or so.  This should allow for steady
strengthening, and the forecast follows the intensity consensus in
calling for the cyclone to become a tropical storm in 12 hours and a
hurricane in about 48 hours.  After 72 hours, a combination of
decreasing sea surface temperatures along the forecast track and
westerly shear is expected to cause the cyclone to weaken.

FORECAST POSITIONS AND MAX WINDS

INIT  30/0300Z  8.2N 125.3W   30 KT  35 MPH
 12H  30/1200Z  8.9N 127.2W   40 KT  45 MPH
 24H  31/0000Z  9.9N 130.1W   50 KT  60 MPH
 36H  31/1200Z 10.9N 133.0W   60 KT  70 MPH
 48H  01/0000Z 12.0N 136.3W   65 KT  75 MPH
 72H  02/0000Z 13.5N 141.5W   75 KT  85 MPH
 96H  03/0000Z 15.5N 145.0W   70 KT  80 MPH
120H  04/0000Z 17.5N 146.5W   65 KT  75 MPH

$$
Forecaster Beven




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