Official Discussion issued by the National Hurricane Center

Nadine (AL152018) DATA RELEASED: 10/9/2018 11:00:00 PM UTC

Copy of official data

Tropical Storm Nadine Discussion Number   4
NWS National Hurricane Center Miami FL       AL152018
1100 PM AST Tue Oct 09 2018

Deep convection has been increasing in the eastern semicircle of
Nadine, with the center close to the western edge of large
convective band.  Overall, the satellite presentation has improved
in the past several hours, although the outflow is limited west of
the center.  While subjective estimates are unchanged from the last
advisory, microwave-based estimates suggest Nadine is somewhat
stronger, so the initial wind speed is set to 40 kt.  Light or
moderate shear is anticipated during the next day or so, along
with sufficiently warm waters, which should promote strengthening.
However, Nadine should encounter a large upper trough after that
time, which will likely cause weakening to begin on Thursday. Later
on, cooler SSTs and strong shear are expected to cause Nadine to
degenerate into a trough of low pressure by the weekend.  The most
significant change is that the model guidance is notably higher
than the last cycle, with a few models even making Nadine a
hurricane eventually.  That seems unlikely given the strength of
the forecast shear, but the forecast is nudged higher than the
previous one and the model consensus.

Nadine continues to turn rightward and is now moving northwestward
at about 7 kt.  This general course is forecast for the next couple
of days due to steering from a mid-level ridge near the Cabo Verde
Islands.  After that time, a west-northwestward or westward turn is
expected as Nadine becomes a shallow system and dissipates.  The
model spread is still fairly wide, with the stronger guidance
generally on the eastern side of the model envelope, and the weaker
guidance on the western side.  There is definitely a slight trend
to the northeast with the latest model guidance, and since we are
expecting a stronger system, the official forecast is adjusted in
that direction, but not nearly as far to the right as most of the
GFS-based guidance.


INIT  10/0300Z 11.6N  31.0W   40 KT  45 MPH
12H  10/1200Z 12.3N  31.7W   45 KT  50 MPH
24H  11/0000Z 13.4N  32.7W   50 KT  60 MPH
36H  11/1200Z 14.8N  33.7W   45 KT  50 MPH
48H  12/0000Z 16.0N  35.0W   35 KT  40 MPH
72H  13/0000Z 17.5N  38.0W   25 KT  30 MPH
96H  14/0000Z...DISSIPATED

Forecaster Blake