ZCZC MIATCDEP5 ALL
TTAA00 KNHC DDHHMM

Tropical Storm Xavier Discussion Number   4
NWS National Hurricane Center Miami FL       EP252018
900 AM MDT Sat Nov 03 2018

Although Xavier is being affected by 20-25 kt of westerly vertical
shear, the cyclone continues to generate a large burst of convection
and the low-level center is now located under the southwestern edge
of the convective mass.  The initial intensity is increased to 45
kt, which is at the upper end of the various satellite intensity
estimates.

During the next 24 h, the dynamical models suggest that an
upper-level trough located to the north and west of Xavier should
provide upper-level divergence over the cyclone.  This could allow
some additional strengthening despite the ongoing shear.  After
that time, the trough is forecast to dissipate, leaving the
tropical storm in an area of upper-level convergence and moderate
to strong shear that should cause it to weaken.  Based on this
evolution, the intensity forecast calls for a little more
strengthening during the next 12-24 h, followed by gradual weakening
through the remainder of the forecast period, with the cyclone
becoming a remnant low in about 96 h.  The forecast follows the
overall trend of the intensity guidance and lies near the upper edge
of the guidance.

Based on a combination of conventional and microwave satellite
fixes, the initial motion is estimated to be 060/7.  There is again
little change to the forecast track philosophy.  Xavier should turn
northeastward and then northward during the next 24 h toward a
weakness in the subtropical ridge created by the aforementioned
trough.  As Xavier weakens and becomes a shallow system, the
cyclone should turn toward the west-northwest and west as it is
steered by the low-level flow to the south of the subtropical ridge.
 The new forecast track is nudged just a little to the east and
north of the previous track, but it remains close to the various
consensus aids.


FORECAST POSITIONS AND MAX WINDS

INIT  03/1500Z 15.3N 107.0W   45 KT  50 MPH
 12H  04/0000Z 15.8N 106.4W   50 KT  60 MPH
 24H  04/1200Z 16.6N 106.0W   50 KT  60 MPH
 36H  05/0000Z 17.3N 106.1W   45 KT  50 MPH
 48H  05/1200Z 17.4N 106.5W   40 KT  45 MPH
 72H  06/1200Z 17.5N 108.0W   30 KT  35 MPH
 96H  07/1200Z 17.5N 111.0W   25 KT  30 MPH...POST-TROP/REMNT LOW
120H  08/1200Z 18.0N 113.5W   20 KT  25 MPH...POST-TROP/REMNT LOW

$$
Forecaster Beven

NNNN