- Search for Search
Tropical Storm POLO

ZCZC MIATCDEP2 ALL
TTAA00 KNHC DDHHMM

TROPICAL STORM POLO DISCUSSION NUMBER  13
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP172014
200 AM PDT FRI SEP 19 2014

Polo is showing a sheared cloud pattern this morning, with the
low-level center located near the northern or northeastern edge of
the convection.  This is consistent with analyses of 20-25 kt of
easterly vertical wind shear impacting the cyclone.  Satellite
intensity estimates are 55 kt from TAFB and 65 kt from SAB, and a
04Z ASCAT overpass showed 50-55 kt winds.  Based on these, the
initial intensity remains 60 kt.

The initial motion is 315/7.  Global models continue to forecast a
ridge of high pressure to develop westward from northern Mexico
during the next several days.  This should cause the track of Polo
to gradually bend toward the west-northwest. By late in the forecast
period, the weakening cyclone should be drifting westward and
southwestward in the shallow low-level flow.  The track guidance
shows little change from the previous advisory through 96 hours, and
then shows a more southwestward drift than forecast earlier.  The
new official forecast follows this, and it is in best agreement with
the consensus model TVCE.

The large-scale models forecast the shear to continue through the
forecast period as Polo moves over progressively cooler sea surface
temperatures.  This should lead to a gradual weakening as shown by
all of the intensity guidance.  The new intensity forecast is
similar to that of the previous advisory, calling for Polo to
weaken to a tropical depression by 96 hours and to degenerate to a
remnant low by 120 hours.


FORECAST POSITIONS AND MAX WINDS

INIT  19/0900Z 18.9N 107.1W   60 KT  70 MPH
 12H  19/1800Z 19.6N 107.9W   55 KT  65 MPH
 24H  20/0600Z 20.4N 108.9W   55 KT  65 MPH
 36H  20/1800Z 21.0N 110.1W   50 KT  60 MPH
 48H  21/0600Z 21.7N 111.5W   45 KT  50 MPH
 72H  22/0600Z 22.5N 114.0W   35 KT  40 MPH
 96H  23/0600Z 22.5N 116.5W   30 KT  35 MPH
120H  24/0600Z 22.0N 117.5W   25 KT  30 MPH...POST-TROP/REMNT LOW

$$
Forecaster Beven

NNNN