000
WTPZ43 KNHC 251444
TCDEP3

Tropical Depression Pilar Discussion Number   8
NWS National Hurricane Center Miami FL       EP182017
900 AM MDT Mon Sep 25 2017

Water vapor satellite imagery indicates that strong southwesterly
vertical wind shear, along with an abundance of dry mid-/upper-level
air, ahead of sharp shortwave trough moving across southern Baja
California is taking its toll on Pilar. Convection has weakened
considerably and has been displaced to the north and east of the
poorly defined low-level circulation center. A blend of Dvorak
satellite T-numbers and current intensity (CI) estimates from TAFB
and SAB is a consensus T2.0/30 kt, resulting in Pilar being
downgraded to a tropical depression. The shear is forecast to
increase to more than 30 kt by 12 h, so continued weakening and
degeneration into a remnant low is forecast today, followed by
dissipation on Tuesday...if not sooner.

The initial motion estimate is 335/06 kt. Pilar and its remnants are
expected to continue moving in this general direction, accompanied
by a slight decrease in forward speed, for the next day or so until
dissipation occurs.  The new NHC track forecast is similar to the
previous advisory track, and lies close to a blend of the NOAA-HCCA
and TCVA consensus track models.

The main hazard associated with Pilar will continue to be heavy
rainfall, which could trigger life-threatening flash floods and
mudslides, over the states of Nayarit, the southern portion of
Sinaloa, and the southwestern portion of Durango during the next
day or so.

FORECAST POSITIONS AND MAX WINDS

INIT  25/1500Z 22.8N 107.0W   30 KT  35 MPH
 12H  26/0000Z 23.4N 107.3W   25 KT  30 MPH...POST-TROP/REMNT LOW
 24H  26/1200Z...DISSIPATED

$$
Forecaster Stewart