000
WTPZ42 KNHC 270257
TCDEP2

HURRICANE SANDRA DISCUSSION NUMBER  14
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP222015
800 PM MST THU NOV 26 2015

Despite the presence of at least 25 kt of southwesterly vertical
wind shear, the satellite appearance of Sandra unexpectedly improved
near 0000 UTC when the eye became better defined.  Whatever
re-intensification this represents has ended, however, as the eye
has again begun to lose definition.  The initial intensity will be
held at 105 kt for this advisory, and the hurricane could have been
a little stronger than that three hours ago based on satellite
intensity estimates.

After nudging to the left earlier, Sandra has turned a little to
the right with an initial motion of 010/11.  The cyclone is moving
into an area of low-level southerly flow west of a ridge over
southern Mexico and an area of strong mid- to upper-level
southwesterly flow between the ridge and a large trough over the
western United States.  The track guidance indicates that a
general north-northeastward motion should continue until the center
reaches mainland Mexico in about 48 hours, although there is some
spread between the poorly initialized ECMWF on the left side of the
guidance envelope and the better initialized GFS on the right side.
The new forecast track is nudged to the east based mainly on the
current position and motion, and it lies near the center of the
guidance envelope.  It should be noted that some eastward component
of motion is likely to continue as long as Sandra retains a deep
vertical structure, which would help keep the cyclone east of the
Baja California peninsula.

Steadily increasing shear should cause Sandra to rapidly weaken
until the center reaches mainland Mexico.  The new intensity
forecast, which is in good agreement with all of the intensity
guidance is unchanged from the previous forecast.  It continues
to call for Sandra to weaken to a tropical storm before the closest
approach to Baja California and to a remnant low before reaching
mainland Mexico.

Given the eastward shift in the forecast track, the expected
weakening, and the likely decay of the wind field to the west of
the center, a tropical storm warning will not be issued for
southern Baja California at this time.  However, a warning could
still be required later tonight or on Friday.

In addition to heavy rains over portions of Mexico, the remnant
mid-/upper-level moisture associated with Sandra will contribute to
a significant precipitation event expected to occur over portions of
the south-central United States this weekend. For more information
on this event, please see products from the NOAA Weather Prediction
Center and local NWS Weather Forecast Offices.


FORECAST POSITIONS AND MAX WINDS

INIT  27/0300Z 18.0N 109.7W  105 KT 120 MPH
 12H  27/1200Z 19.3N 109.6W   85 KT 100 MPH
 24H  28/0000Z 21.1N 109.3W   65 KT  75 MPH
 36H  28/1200Z 23.2N 108.8W   45 KT  50 MPH
 48H  29/0000Z 25.0N 108.1W   30 KT  35 MPH...POST-TROP/INLAND
 72H  30/0000Z 28.0N 107.0W   15 KT  15 MPH...POST-TROP/INLAND
 96H  01/0000Z...DISSIPATED

$$
Forecaster Beven