276 
WTPZ45 KNHC 020851
TCDEP5

Tropical Depression Rosa Discussion Number  29
NWS National Hurricane Center Miami FL       EP202018
300 AM MDT Tue Oct 02 2018

Satellite imagery continues to show a lack of convection near
the center of Rosa this morning.  The remaining convection is
located well northeast of the center, and is spreading inland over
northern Mexico and portions of the Desert Southwest.  A couple of
partial ASCAT passes revealed an area of 25-30 kt winds over the
central Gulf of California, and this is the basis for reducing the
initial intensity to 30 kt.  The data also suggest that the
circulation has become elongated and that a new center may be
forming near the northeastern coast of the Baja California
peninsula.

The initial motion estimate is 030/9 kt.  Rosa is expected to move
northeastward between a deep-layer ridge over northern Mexico and a
mid- to upper-level trough over the northeastern Pacific. These
steering features should bring the center of Rosa across the
northern Gulf of California and into northern Mexico this afternoon.
Southwesterly shear and land interaction should cause the cyclone to
continue to weaken today, and Rosa is expected to dissipate over
northern Mexico or southwestern Arizona by tonight.

Although Rosa is forecast to weaken, the system is still expected
to bring heavy rainfall and life-threatening flash flooding to
portions of northwestern Mexico and the Desert Southwest during
the next day or so.


Key Messages:

1. The main hazard expected from Rosa or its remnants is very heavy
rainfall in Baja California, northwestern Sonora, and the U.S.
Desert Southwest.  These rains are expected to produce
life-threatening flash flooding and debris flows in the deserts, and
landslides in mountainous terrain.  For more information about
potential rainfall in those areas, please see products from the
Weather Prediction Center and your local NWS forecast office.


FORECAST POSITIONS AND MAX WINDS

INIT  02/0900Z 29.3N 114.9W   30 KT  35 MPH
 12H  02/1800Z 31.8N 114.0W   25 KT  30 MPH...POST-TROP/INLAND
 24H  03/0600Z...DISSIPATED

$$
Forecaster Brown