BULLETIN
Tropical Storm Xavier Advisory Number 9
NWS National Hurricane Center Miami FL EP252018
300 PM CST Sun Nov 04 2018
...XAVIER MOVING SLOWLY NORTHWARD OFF THE COASTS OF COLIMA AND
JALISCO...
...HEAVY SHOWERS AND GUSTY WINDS OCCURRING ALONG PORTIONS OF THE
COAST OF SOUTHWESTERN MEXICO...
SUMMARY OF 300 PM CST...2100 UTC...INFORMATION
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LOCATION...18.1N 105.5W
ABOUT 100 MI...160 KM SW OF MANZANILLO MEXICO
MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H
PRESENT MOVEMENT...N OR 350 DEGREES AT 6 MPH...9 KM/H
MINIMUM CENTRAL PRESSURE...1001 MB...29.56 INCHES
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Tropical Storm Xavier Discussion Number 9
NWS National Hurricane Center Miami FL EP252018
300 PM CST Sun Nov 04 2018
After being sheared off this morning, deep convection has
redeveloped and persisted over Xavier's center of circulation.
Dvorak Current Intensity numbers from TAFB and SAB remain 3.0, and
the latest UW-CIMSS SATCON estimate is 43 kt. The initial intensity
therefore remains 45 kt. Although shear analyses indicate that
about 25 kt of southwesterly shear is affecting Xavier, an
upper-level trough in the vicinity appears to be producing a decent
amount of divergence aloft to support the ongoing convection. The
global models show that trough dissipating and the upper flow
becoming unidirectional within 12 hours, which should cut off the
divergence and allow the adverse effects of shear and dry air to
take over. As a result, gradual weakening is expected during the
next couple of days, and Xavier may cease to produce organized deep
convection (and thus become a remnant low) in 36-48 hours. The
remnant low should dissipate by day 4, if not sooner. The updated
NHC intensity forecast is conservative, following continuity from
the previous forecast and lying near the upper bound of the
intensity models.
Xavier's motion still appears to be slowly northward, or 350/5 kt.
The global models, most of which assume that Xavier will become a
shallow system soon, show the cyclone turning northwestward and
west-northwestward during the next 24 hours. While this seems
reasonable, as long as Xavier maintains vertical integrity, it will
likely continue moving closer to the right side of the guidance
envelope. With the assumption that deep convection won't dissipate
right away, the NHC track forecast is to the right of the consensus
aids, close to the ECMWF solution, during the first 24 hours.
After 24 hours, it remains close to the TVCN multi-model consensus.
A 1600 UTC ASCAT pass indicated that Xavier's tropical-storm-force
wind field on the east side was larger than previously estimated,
with those winds lying near the coast of southwestern Mexico. As a
result, the government of Mexico issued a Tropical Storm Warning for
a portion of the coasts of Michoacan, Colima, and Jalisco. Locally
heavy rainfall and large swells are also likely to affect the coast
of southwestern Mexico during the next day or two.
FORECAST POSITIONS AND MAX WINDS
INIT 04/2100Z 18.1N 105.5W 45 KT 50 MPH
12H 05/0600Z 18.7N 106.0W 40 KT 45 MPH
24H 05/1800Z 19.2N 107.1W 35 KT 40 MPH
36H 06/0600Z 19.5N 108.2W 30 KT 35 MPH
48H 06/1800Z 19.6N 109.5W 25 KT 30 MPH...POST-TROP/REMNT LOW
72H 07/1800Z 19.4N 111.8W 20 KT 25 MPH...POST-TROP/REMNT LOW
96H 08/1800Z 19.0N 114.0W 15 KT 15 MPH...POST-TROP/REMNT LOW
120H 09/1800Z...DISSIPATED
$$
Forecaster Berg