000
WTPZ44 KNHC 200905 CCA
TCDEP4

Tropical Depression Twenty-Four-E Discussion Number   1...Corrected
NWS National Hurricane Center Miami FL       EP242018
400 AM CDT Sat Oct 20 2018

Corrected advisory number from 2 to 1

Various satellite data indicate that the area of low pressure that
NHC has been monitoring off the coast of southern Mexico for thew
past few days has acquired enough convective organization to be
designated as a tropical depression, the twenty-fourth one of the
very busy 2018 eastern North Pacific hurricane season. Although the
depression is a sheared system, some banding features have recently
developed south of the center, while overshooting cloud tops just
west of the center are quite cold -85 to -91 deg C). The initial
intensity is set to 30 kt based on a satellite intensity estimate of
T2.0/30 kt from both TAFB and SAB.

The initial motion estimate is 280/08 kt, based primarily on passive
microwave fixes and GOES-16 nighttime imagery. A gradual turn toward
the west-northwest is expected by this afternoon, followed by a
slower northwestward motion on Sunday as the system moves along the
southwestern periphery of a weakening mid-level ridge. A slow
northwestward motion is expected to continue into early next week
while the ridge to the north changes little.  On days 4 and 5,
however, a series of weak shortwave troughs are forecast to move
through the larger scale southwesterly flow locked in over the
southwestern U.S. and northern Mexico, causing an erosion of the
western portion of the ridge, which should allow the cyclone to
gradually recurve northward and north-northeastward. The NHC model
guidance is in good agreement overall on this developing track
scenario, and the official forecast track lies between the HCCA and
TVCE track consensus aids.

The depression is expected to steadily strengthen during the next 96
hours due to very favorable environmental conditions consisting of
low vertical wind shear (less than 10 kt), high amounts of mid-level
moisture, and warm 28-30 deg C SSTs.  As a result, the cyclone is
expected to become a tropical storm later this morning, a hurricane
by Sunday night, and be near major hurricane strength by Wednesday.
Given the very favorable conditions expected on Sunday and Monday,
there is a fair chance of rapid intensification occurring similar to
that depicted by the COAMPS-TC and HMON models, which bring the
cyclone to category-4 status around 72 hours. The NHC official
intensity forecast near the HCCA and IVCN consensus models through
96 hours, and then a little above the guidance at 120 hours despite
an increase in the shear expected at that time.

FORECAST POSITIONS AND MAX WINDS

INIT  20/0900Z 15.1N 104.9W   30 KT  35 MPH
 12H  20/1800Z 15.5N 105.7W   40 KT  45 MPH
 24H  21/0600Z 15.9N 106.6W   50 KT  60 MPH
 36H  21/1800Z 16.5N 107.4W   60 KT  70 MPH
 48H  22/0600Z 17.1N 108.0W   75 KT  85 MPH
 72H  23/0600Z 18.0N 109.0W   90 KT 105 MPH
 96H  24/0600Z 19.2N 109.4W  100 KT 115 MPH
120H  25/0600Z 21.7N 108.5W   95 KT 110 MPH

$$
Forecaster Stewart