000
WTPZ45 KNHC 060234
TCDEP5

TROPICAL DEPRESSION FIFTEEN-E DISCUSSION NUMBER   1
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP152015
900 PM MDT SAT SEP 05 2015

Satellite images indicate that the area of low pressure located
southwest of Mexico now has a well-defined center and organized
deep convection.  Therefore, it is now a tropical depression, with
the current intensity of 30 kt based on the latest satellite
estimate from TAFB.  Buoy 43546 also reported a pressure of
1001.4 mb a couple of hours ago while the center passed.

Moderate northeasterly shear is forecast to decrease by the global
models by late tomorrow, which should allow the depression to
intensify into a tropical storm.  Thereafter, very warm waters, high
values of mid-level moisture and light shear are expected through
Tuesday.  These conditions should promote strengthening to a
hurricane early next week, with almost all of the guidance agreeing
with this general scenario.  Thereafter, SSTs are expected to become
marginal by day 4, with an increase in shear also in the forecast,
likely causing weakening by that time. The NHC wind speed prediction
is near or above the model consensus for most of the forecast
period.

The depression is moving northwestward at about 9 kt.  This general
motion is expected for the next 2-3 days while the cyclone remains
on the southwestern side of a large mid-level ridge over Mexico.
Models are in fairly good agreement on this scenario through that
time.  The forecast is more challenging in the longer range due to
various depictions of the strength of the ridge over the eastern
Pacific and the vertical depth of the tropical cyclone.  Given the
uncertainties, the official forecast stays fairly close to the model
consensus at days 4 and 5, but leans in the direction of the ECMWF.

FORECAST POSITIONS AND MAX WINDS

INIT  06/0300Z 13.1N 107.2W   30 KT  35 MPH
 12H  06/1200Z 14.1N 108.1W   35 KT  40 MPH
 24H  07/0000Z 15.5N 109.6W   45 KT  50 MPH
 36H  07/1200Z 17.0N 111.1W   55 KT  65 MPH
 48H  08/0000Z 18.5N 112.6W   65 KT  75 MPH
 72H  09/0000Z 20.2N 115.5W   65 KT  75 MPH
 96H  10/0000Z 21.5N 118.0W   60 KT  70 MPH
120H  11/0000Z 22.5N 121.0W   50 KT  60 MPH

$$
Forecaster Blake