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Tropical Storm ROSA


Tropical Storm Rosa Discussion Number  27
NWS National Hurricane Center Miami FL       EP202018
200 PM PDT Mon Oct 01 2018

Rosa has no deep convection near its center, but there are plenty
of rain-bearing clouds over areas well to the north and northeast of
the center, including the northern Baja California peninsula,
Sonora, and portions of the southwestern United States.  The
scatterometer recently missed Rosa, but assuming a steady spin down
since the last overpass 12 hours ago, the advisory intensity is set
at 35 kt. Continued weakening, due to very strong vertical shear,
cool waters, and then interaction with land, should reduce Rosa to a
tropical depression very soon.  Rosa is likely to degenerate into a
remnant low over the southwestern United States tomorrow.

The cyclone continues moving north-northeastward, or 030/9 kt.  The
track forecast philosophy is the same as in the previous advisory
package.  The flow ahead of a broad mid-level trough should advect
Rosa, or its remnant, north-northeastward until dissipation.  The
official track forecast continues to follow the multi-model
consensus closely.

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 that area, please see products from the
Weather Prediction Center and your local NWS forecast office.

2. Tropical storm conditions are affecting portions of the
central and northern Baja California peninsula,  especially over
higher elevations.  These conditions could spread into the northern
Gulf of California later tonight. Interests in those locations
should monitor the progress of Rosa.


INIT  01/2100Z 28.1N 116.2W   35 KT  40 MPH
 12H  02/0600Z 29.9N 115.2W   30 KT  35 MPH...INLAND
 24H  02/1800Z 32.7N 114.0W   25 KT  30 MPH...POST-TROP/INLAND
 36H  03/0600Z 35.5N 113.0W   20 KT  25 MPH...POST-TROP/INLAND
 48H  03/1800Z...DISSIPATED

Forecaster Pasch