000
WTPZ41 KNHC 020842
TCDEP1

TROPICAL STORM VANCE DISCUSSION NUMBER  13
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP212014
100 AM PST SUN NOV 02 2014

After struggling to organize during the past couple of days, Vance
is finally in the midst of a definitive strengthening trend, and
close to becoming a hurricane.  The low-level center is embedded
beneath very cold cloud tops, and the convective canopy has been
expanding due to good upper-level outflow to the north and west of
the cyclone.  The initial intensity is estimated to be 60 kt based
on a blend of Dvorak estimates of T3.5/55 kt from TAFB, T4.0/65 kt
from SAB, and T3.7/59 kt from the UW-CIMSS ADT.

Vance is likely going through a period of rapid intensification.
Atmospheric and oceanic conditions are favorable for additional
quick strengthening, and there is a 2 out of 3 chance of a 30-kt
increase in Vance's maximum winds during the next 24 hours based on
the SHIPS Rapid Intensification guidance.  The new NHC intensity
forecast has been raised from the previous forecast during the first
48 hours, and it is slightly higher than the most aggressive
intensity models in light of the SHIPS RI numbers.  After 48 hours,
Vance is likely to weaken rapidly due to 30-40 kt of southwesterly
shear and a drier mid-level environment.  The NHC forecast is
essentially unchanged from the previous one on days 3-5 and closely
follows the SHIPS guidance and the trends noted in the GFS and ECMWF
global models.

Vance is moving a little faster toward the west-northwest, or
295/12 kt.  The cyclone is moving along the southwestern periphery
of a mid-level ridge centered over southern Mexico, and toward a
deep-layer trough located between 110W and 130W.  Vance is expected
to turn northwestward and northward between these two features
during the next 2 days.  Thereafter, the strong shear is forecast
to leave Vance's low-level circulation in a weaker steering
environment south of the Baja California peninsula.  The track
guidance has shifted westward, especially after 48 hours, and the
NHC track forecast lies on the eastern edge of the envelope near the
GFS and ECMWF solutions.

FORECAST POSITIONS AND MAX WINDS

INIT  02/0900Z 10.9N 106.5W   60 KT  70 MPH
 12H  02/1800Z 12.0N 108.2W   70 KT  80 MPH
 24H  03/0600Z 13.7N 110.0W   80 KT  90 MPH
 36H  03/1800Z 15.5N 110.7W   80 KT  90 MPH
 48H  04/0600Z 17.1N 110.7W   70 KT  80 MPH
 72H  05/0600Z 18.9N 109.9W   45 KT  50 MPH
 96H  06/0600Z 20.5N 109.5W   20 KT  25 MPH...POST-TROP/REMNT LOW
120H  07/0600Z 22.0N 111.5W   15 KT  15 MPH...POST-TROP/REMNT LOW

$$
Forecaster Berg