000
WTPZ41 KNHC 120855
TCDEP1
 
Tropical Storm Sergio Discussion Number  52
NWS National Hurricane Center Miami FL       EP212018
300 AM MDT Fri Oct 12 2018
 
Sergio's cloud shield is well separated from the poorly organized
surface circulation and is confined to the northwest quadrant.
Subjective satellite intensity estimates yield a reduction in the
initial intensity to 45 kt for this advisory.
 
Weakening should continue this morning due to cool oceanic sea
surface temperatures and belligerent southwesterly shear, but
Sergio is still expected to be a tropical storm as it make landfall
in the Pacific coast of Baja California Sur. Afterward, Sergio
should quickly become a depression and eventually dissipate as it
traverses the rugged terrain of the northwestern Mexico state of
Sonora.
 
The initial motion is estimated to be northeastward, or 045/21
kt, within the deep-layer southwesterly flow produced by a
mid-latitude trough situated just west of the California coast.
This synoptic steering pattern should steer Sergio toward the
northeast at an accelerated rate of speed.  A 36 hour
post-tropical/remnant low point is maintained to simply represent
the inland motion of Sergio.  The NHC forecast lies in the middle of
the various multi-model consensus aids, and is basically an update
of the previous package.
 
The primary threat associated with Sergio and its remnants continues
to be life-threatening flash flooding and mudslides within
mountainous terrain in the Mexico states of Baja California Sur,
Sonora, the U.S. Southern Plains, and Arkansas through the weekend.
For more information about this potential hazard, see products from
the Weather Prediction Center and your local weather forecast
office.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  12/0900Z 26.1N 113.8W   45 KT  50 MPH
 12H  12/1800Z 28.2N 111.2W   30 KT  35 MPH...INLAND
 24H  13/0600Z 31.0N 107.2W   25 KT  30 MPH...POST-TROP/REMNT LOW
 36H  13/1800Z 33.8N 103.2W   15 KT  15 MPH...POST-TROP/REMNT LOW
 48H  14/0600Z...DISSIPATED
 
$$
Forecaster Roberts