000
WTPZ41 KNHC 150234
TCDEP1

HURRICANE KARINA DISCUSSION NUMBER   9
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP112014
800 PM PDT THU AUG 14 2014

Karina's structure has degraded significantly since the last
advisory.  A 2326 UTC AMSU pass showed that the low-level center has
become displaced from the deep convection due to 20-25 kt of
easterly shear, as diagnosed by CIMSS at the University of
Wisconsin.  In addition, cloud top temperatures have warmed during
the past few hours.  The initial intensity remains 65 kt based on
the latest TAFB Dvorak estimate, but this could be a little
generous.

The recent evolution of Karina's structure makes the intensity
forecast quite tricky.  The SHIPS and LGEM models appear to be
responding to less of a positive contribution from persistence and
GOES satellite predictors, and show much less strengthening than
before.  The GFDL and HWRF, on the other hand, continue their
pattern of showing more immediate weakening.  Since vertical shear
is expected to remain rather strong for another 36-48 hours, Karina
may have a difficult time recovering.  Therefore, the new NHC
intensity forecast has been lowered for the entire forecast period
but still lies above all of the guidance, especially beyond 24
hours.  If Karina cannot recover soon, however, subsequent forecasts
will likely require additional decreases to fall in line with the
preponderance of the intensity model solutions.

The mid-tropospheric pattern consists of a mid-level high centered
over the southwestern U.S. with a ridge extending west-southwestward
over the Pacific.  The ridge is steering Karina westward, or
270/11 kt, and the subtropical ridge is expected to keep the cyclone
on a westward or west-northwestward track through the forecast
period.  Karina could begin to interact with one or two adjacent
disturbances toward the end of the forecast period, possibly forcing
it to move west-southwestward and at a slower speed by day 5.  The
track guidance envelope shifted to the north on this cycle, but it
was not enough to require a significant change from the previous
official forecast.

FORECAST POSITIONS AND MAX WINDS

INIT  15/0300Z 17.1N 118.3W   65 KT  75 MPH
 12H  15/1200Z 17.4N 119.9W   70 KT  80 MPH
 24H  16/0000Z 17.9N 122.0W   70 KT  80 MPH
 36H  16/1200Z 18.3N 124.2W   70 KT  80 MPH
 48H  17/0000Z 18.4N 126.4W   70 KT  80 MPH
 72H  18/0000Z 18.0N 130.5W   65 KT  75 MPH
 96H  19/0000Z 17.5N 133.5W   65 KT  75 MPH
120H  20/0000Z 17.0N 136.0W   60 KT  70 MPH

$$
Forecaster Berg