000
WTPZ41 KNHC 171437
TCDEP1

TROPICAL STORM ESTELLE DISCUSSION NUMBER   9
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP062016
900 AM MDT SUN JUL 17 2016

A large burst of deep convection developed over the center of
Estelle overnight and continues this morning.  A timely SSMIS
microwave overpass was very helpful in examining the structure and
center location of the tropical cyclone.  The microwave data
revealed a well-defined low-level ring located near the northwestern
edge of the primary convective band, but there was no evidence of a
mid-level eye.  The latest Dvorak T-numbers from SAB and TAFB
are 3.5 and 4.0, respectively, and UW/CIMSS ADT estimates have
risen to T3.5/55 kt.  These data support an initial wind speed
of 55 kt for this advisory.

The initial motion estimate is 285/7 kt. A strong subtropical ridge
to the north of Estelle should keep the tropical cyclone moving on
a westward to west-northwestward heading during the next several
days. Near the end of the forecast period, Estelle will be
approaching the western portion of the ridge, which should allow the
tropical cyclone to gain more latitude.  The guidance is more
tightly clustered today than it was 24 hours ago, so there is
increased confidence in the track forecast.  The new NHC track is
near the Florida State Superensemble and an average of the GFS/ECMWF
models.

There appears to be some north or northwesterly shear still
affecting Estelle, but the shear is not expected to be strong
enough to prevent intensification during the next day or so. After
that time, the shear is forecast to relax, and Estelle is forecast
to strengthen at a faster rate on Monday.  The track of the tropical
cyclone brings it over cooler waters in 2 to 3 days, which should
start the weakening process, and it should continue throughout the
remainder of the forecast period.  The updated intensity forecast is
similar to the previous advisory, and is closest to the Florida
State Superensemble and the intensity consensus IVCN.

FORECAST POSITIONS AND MAX WINDS

INIT  17/1500Z 16.3N 111.8W   55 KT  65 MPH
 12H  18/0000Z 16.6N 112.9W   65 KT  75 MPH
 24H  18/1200Z 17.2N 114.6W   70 KT  80 MPH
 36H  19/0000Z 17.6N 116.3W   80 KT  90 MPH
 48H  19/1200Z 17.9N 118.1W   85 KT 100 MPH
 72H  20/1200Z 18.2N 122.2W   80 KT  90 MPH
 96H  21/1200Z 19.0N 127.0W   65 KT  75 MPH
120H  22/1200Z 20.8N 132.5W   45 KT  50 MPH

$$
Forecaster Brown