000
WTPZ42 KNHC 162034
TCDEP2

TROPICAL STORM POLO DISCUSSION NUMBER   3
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP172014
200 PM PDT TUE SEP 16 2014

The cloud pattern is gradually becoming better organized, with very
well defined cyclonically curved convective bands wrapping around a
small central dense overcast. An ASCAT-B pass over the cyclone
a few hours ago yields an initial intensity of 40 kt. The ocean is
plenty warm south of Mexico, and the shear is expected to decrease
during the next day or two. On this basis, the NHC forecast calls
for strengthening, making Polo a hurricane in about 36 hours, in
good agreement with the model consensus ICON. After 48 hours, most
of the guidance shows an increase in shear and no additional
development is anticipated, and in fact, some gradual weakening
should then begin.

Polo is moving toward the northwest or 305 degrees at about 10
kt, steered by the flow around a mid-level ridge over the
southwestern United States and northern Mexico. This ridge will
continue to steer Polo on a track parallel to and not too far from
the southwest coast of Mexico, and take the cyclone well south
of the Baja California peninsula. The ECMWF model, which
previously brought the cyclone closer to Mexico, has changed its
tune, and now keeps the cyclone offshore like the solution of the
GFS. This is reflected in a southward shift in the multi-model
consensus TVCN, which is very close to the NHC forecast.

FORECAST POSITIONS AND MAX WINDS

INIT  16/2100Z 13.2N 100.4W   40 KT  45 MPH
 12H  17/0600Z 14.2N 101.5W   50 KT  60 MPH
 24H  17/1800Z 15.7N 103.0W   55 KT  65 MPH
 36H  18/0600Z 16.8N 104.5W   65 KT  75 MPH
 48H  18/1800Z 17.8N 106.0W   70 KT  80 MPH
 72H  19/1800Z 19.5N 108.0W   65 KT  75 MPH
 96H  20/1800Z 21.0N 110.0W   60 KT  70 MPH
120H  21/1800Z 22.5N 113.0W   50 KT  60 MPH

$$
Forecaster Avila