000
WTPZ41 KNHC 161433
TCDEP1

TROPICAL STORM KARINA DISCUSSION NUMBER  15
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP112014
800 AM PDT SAT AUG 16 2014

The center of Karina is located on the northeastern edge of a
circular area of very deep convection due to moderate easterly
vertical wind shear. Satellite intensity estimates from TAFB and SAB
continue to support an initial intensity of 40 knots. Most of the
global guidance as well as the SHIPS model indicate that the shear
will persist for the next 24 to 36 hours while a portion of the
circulation is over relatively cooler waters. On this basis, the NHC
forecast indicate some slight weakening during the next day or so.
After that time, the shear could relax some and the cyclone
will likely turn west-southwestward toward warmer waters. This
should result in some intensification as suggested by the intensity
consensus. HWRF is the most aggressive model forecasting Karina back
to hurricane status.

It appears that the expected amplification of the ridge to the north
of Karina is already materializing, and the cyclone is now moving
toward the west or 270 degrees at 9 knots. The ridge will continue
to build westward as indicated by global models, and this pattern
will force the cyclone to move toward the west-southwest for the
next 3 days or so. By then, the steering currents are expected to
collapse when several disturbances develop nearby. This will likely
cause Karina to meander for the remainder of the forecast
period. Track guidance has not change and continues to support
both the west-southwest track and the decrease in forward speed
indicated by NHC, which in fact, is very close to the multi-model
consensus.


FORECAST POSITIONS AND MAX WINDS

INIT  16/1500Z 18.3N 124.1W   40 KT  45 MPH
 12H  17/0000Z 18.4N 125.7W   35 KT  40 MPH
 24H  17/1200Z 18.3N 127.6W   35 KT  40 MPH
 36H  18/0000Z 17.8N 129.5W   35 KT  40 MPH
 48H  18/1200Z 17.5N 131.0W   40 KT  45 MPH
 72H  19/1200Z 16.5N 133.0W   40 KT  45 MPH
 96H  20/1200Z 16.5N 134.0W   45 KT  50 MPH
120H  21/1200Z 16.8N 134.3W   50 KT  60 MPH

$$
Forecaster Avila