000
WTPZ41 KNHC 170832
TCDEP1

TROPICAL STORM KARINA DISCUSSION NUMBER  18
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP112014
200 AM PDT SUN AUG 17 2014

Although Karina is producing a little more deep convection than it
was earlier this evening, the system has a sheared appearance with
the low-level center located near the eastern edge of the deep
cloudiness.  A pair of ASCAT passes around 0600 UTC showed maximum
winds of around 35 kt to the west of the center, therefore, the
initial intensity is held at that value.  This wind speed estimate
is also in fair agreement with Dvorak T-numbers from TAFB, SAB, and
UW-CIMSS ADT.  Only slight strengthening is forecast as the
environmental conditions are not expected to change much during the
next several days, with the shear predicted to remain moderate and
sea surface temperatures marginal.  The NHC intensity forecast is
slightly lower than the previous one to be closer to the latest
guidance.

Karina is moving just south of due west at about 9 kt.  A west to
southwest motion is forecast during the next 2 to 3 days while the
storm remains steered by the subtropical ridge to the north of the
system.  Beyond that time, the cyclone is likely to stall or move
erratically when the steering currents significantly weaken in
response to developing tropical disturbances both to the west
and east of Karina.  Although a considerable amount of spread in
the models exist, they do agree on this general scenario.  The NHC
track forecast lies fairly close to the multi-model consensus.

FORECAST POSITIONS AND MAX WINDS

INIT  17/0900Z 17.9N 127.0W   35 KT  40 MPH
 12H  17/1800Z 17.6N 128.2W   35 KT  40 MPH
 24H  18/0600Z 17.1N 130.0W   40 KT  45 MPH
 36H  18/1800Z 16.4N 131.4W   40 KT  45 MPH
 48H  19/0600Z 16.1N 132.2W   45 KT  50 MPH
 72H  20/0600Z 16.1N 133.0W   45 KT  50 MPH
 96H  21/0600Z 16.1N 133.5W   45 KT  50 MPH
120H  22/0600Z 16.1N 133.5W   45 KT  50 MPH

$$
Forecaster Cangialosi