000
WTNT45 KNHC 101449
TCDAT5

Tropical Storm Nadine Discussion Number   6
NWS National Hurricane Center Miami FL       AL152018
1100 AM AST Wed Oct 10 2018

Several microwave overpasses after 0600 UTC indicated that Nadine
very quickly developed a well-defined mid-level eye overnight.
This signature is typically associated with strengthening tropical
cyclones. Although more recent visible imagery indicates that strong
shear has since caused the cyclone to become tilted with height, a
pair of ASCAT passes around 1200 UTC indicated maximum winds of
45-50 kt.  Given the small size of the tropical storm, the ASCAT
likely under-sampled the true maximum, so the initial intensity has
been raised to 55 kt.  Due to limitations in our ability to observe
the intensity of small tropical storms far from land, it should be
noted that this estimate is fairly uncertain.

Since the tropical storm appears to have become more tilted since
last night, further strengthening is not likely.  Shear analysis
from UW-CIMSS shows that Nadine is moving into a region of 20-30 kt
of westerly shear, and SHIPS diagnostics indicate that the shear
could increase to near 40 kt in another couple of days.  All of the
intensity guidance indicates that Nadine will weaken quickly by
tomorrow, and it could become a depression by 72 h.  Dissipation
will likely follow shortly after, as shown by nearly all of the
global and regional models.

The aforementioned ASCAT passes were very helpful in locating the
center of Nadine at 1200 UTC, and the tropical storm is moving
northwestward, or 325/6 kt.  A northwestward to north-northwestward
motion at a similar forward speed is anticipated for the next day or
two.  By Friday, a turn toward the west will likely begin as the
low-level circulation of Nadine becomes separated from its
convection and turns westward in the low-level easterlies. Nadine
is essentially on the track of the previous NHC forecast, and no
significant changes to the track forecast were required.


FORECAST POSITIONS AND MAX WINDS

INIT  10/1500Z 12.6N  31.6W   55 KT  65 MPH
 12H  11/0000Z 13.5N  32.1W   55 KT  65 MPH
 24H  11/1200Z 14.6N  32.9W   50 KT  60 MPH
 36H  12/0000Z 15.7N  33.9W   45 KT  50 MPH
 48H  12/1200Z 16.5N  35.2W   35 KT  40 MPH
 72H  13/1200Z 17.5N  39.1W   30 KT  35 MPH
 96H  14/1200Z...DISSIPATED

$$
Forecaster Zelinsky