000
WTPZ42 KNHC 161457
TCDEP2

TROPICAL STORM POLO DISCUSSION NUMBER   2
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP172014
800 AM PDT TUE SEP 16 2014

Microwave data earlier today indicated that the center of
Polo was to the north of the main convection due to moderate
northeasterly shear.  Since that time, the thunderstorm
activity has increased near the center despite the shear, but
the cloud pattern is still somewhat disrupted. Dvorak intensity
numbers support an initial intensity of 35 kt. The ocean is plenty
warm in that area, and with the shear expected to decrease, the NHC
forecast calls for strengthening, making Polo a hurricane in about
48 hours.  This is in good agreement with the intensity consensus
ICON.

Polo is moving toward the northwest or 310 degrees at about 10
kt. The flow around a mid-level ridge over the southwestern
United States and northern Mexico is controlling the track of
Polo. This ridge is forecast to persist, keeping Polo on a general
northwestward track for the next 3 to 4 days. The ECMWF
model forecasts the ridge to weaken faster than the GFS, bringing
the center of the storm closer to the coast. At this time, the NHC
forecast follows the multi-model consensus TVCN, and the average
track between the GFS and the ECMWF, keeping Polo on a track
parallel to the southwest coast of Mexico. Polo is expected to turn
to the west by the end of the forecast period as a ridge to the
north rebuilds.

The government of Mexico has issued a tropical storm watch for a
portion of the coast of southwestern Mexico from Zihuatanejo to
Cabo Corrientes.


FORECAST POSITIONS AND MAX WINDS

INIT  16/1500Z 12.8N  99.4W   35 KT  40 MPH
 12H  17/0000Z 13.8N 100.6W   45 KT  50 MPH
 24H  17/1200Z 15.0N 102.0W   55 KT  65 MPH
 36H  18/0000Z 16.3N 103.8W   60 KT  70 MPH
 48H  18/1200Z 17.5N 105.3W   65 KT  75 MPH
 72H  19/1200Z 19.5N 108.0W   65 KT  75 MPH
 96H  20/1200Z 21.0N 110.0W   65 KT  75 MPH
120H  21/1200Z 22.0N 112.0W   55 KT  65 MPH

$$
Forecaster Avila