000
WTPZ41 KNHC 241447
TCDEP1

TROPICAL STORM KARINA DISCUSSION NUMBER  47
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP112014
800 AM PDT SUN AUG 24 2014

Karina's deep convection has expanded some this morning, and the
strong temperature gradient in the infrared imagery on the east side
of the cyclone has weakened.  Both would be indicative of the large
vertical shear diminishing some, consistent with the CIMSS analysis
of 5-10 kt shear.  The GFS-based SHIPS shear, on the other hand, is
diagnosed as being about 20 kt.  The intensity estimates widely
range from 45-75 kt, depending on whether a shear or embedded center
pattern is used in the Dvorak technique. The initial intensity is
lowered slightly to 55 kt, but this estimate has more than the usual
uncertainty.  Even if the shear has subsided some currently, this
should pick up more shortly as the outflow from major hurricane
Marie affects Karina.  The combination of strong vertical shear,
marginally warm SSTs, and fairly dry air should lead to at least a
gradual - if not quick - weakening of the tropical cyclone.  The
intensity forecast is based upon a blend of the SHIPS, LGEM, and
HWRF models and is quite similar to that from the previous advisory.

An ASCAT pass from late last night indicated tropical-storm-force
winds extending out about 60 nm on the eastern semi-circle.  The
initial size is assessed the same as that previously, and a gradual
reduction in tropical-storm-force wind radii is anticipated as the
cyclone weakens.

Karina is being steered east-northeastward at 8 kt around the large
circulation of post-tropical Lowell to its north-northeast.  The
absence of microwave imagery over Karina and the lack of visible
imagery before sunrise makes the current position and motion
somewhat unclear. The steering influence of Lowell will diminish in
about a day as the distance between the systems increases, and
Karina should respond by slowing down and turning gradually to the
east-southeast.  In about two days, Karina's track will mainly be
influenced by the approaching very large and strong Marie.  Karina
should be accelerated along toward the east until it becomes
absorbed within Marie in about three to four days.  The forecast
track is based upon a blend of the GFS, GFDL, HWRF, and ECMWF models
and is slightly faster than that issued in the previous advisory.

FORECAST POSITIONS AND MAX WINDS

INIT  24/1500Z 18.0N 131.4W   55 KT  65 MPH
 12H  25/0000Z 18.0N 130.1W   45 KT  50 MPH
 24H  25/1200Z 18.0N 128.7W   35 KT  40 MPH
 36H  26/0000Z 17.8N 127.9W   30 KT  35 MPH
 48H  26/1200Z 17.5N 127.3W   25 KT  30 MPH
 72H  27/1200Z 16.9N 124.3W   25 KT  30 MPH...POST-TROP/REMNT LOW
 96H  28/1200Z...DISSIPATED

$$
Forecaster Landsea