TROPICAL STORM TINA DISCUSSION NUMBER 1
NWS NATIONAL HURRICANE CENTER MIAMI FL EP212016
900 PM MDT SUN NOV 13 2016
Organized deep convection has developed closer to the center of the
low pressure system located a couple of hundred miles southwest of
the southwestern coast of Mexico since this afternoon. On this
basis, the system is being designated as a tropical storm with 35
kt winds, in agreement with a satellite classification of T2.5 from
TAFB and earlier ASCAT data. Even though Tina is over 30 deg C
waters, a large mid- to upper-level trough extending southwestward
into the eastern Pacific from the central United States is imparting
around 30 kt of south-southwesterly shear over the cyclone. This
shear is forecast to increase further during the next 24 hours when
a piece of the trough amplifies over the Gulf of Mexico, and this
should cause Tina to degenerate into a remnant low. The NHC
intensity forecast is consistent with the statistical-dynamical
guidance and shows dissipation by 48 hours.
The initial motion estimate is 350/03. In the very short term,
Tina should continue to move generally northward, or possibly
even erratically toward the current convective burst, in a deep
layer of south-southwesterly flow. Within about 12 hours, the shear
is forecast to be extremely strong and result in a decoupling of the
cyclone. Once this occurs, Tina should turn west-northwestward and
westward into the low-level flow around the eastern Pacific
subtropical ridge. The NHC forecast track is a little to the right
of all of the guidance through 12 hours and then merges with the
multi-model consensus until dissipation.