000
WTPZ41 KNHC 220859
TCDEP1

TROPICAL STORM KARINA DISCUSSION NUMBER  38
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP112014
200 AM PDT FRI AUG 22 2014

Karina's convective structure has changed little during the past
few hours.  An 0613 UTC ASCAT-B pass just clipped the western
portion of the cyclone's circulation and showed some reliable 50-kt
barbs.  Therefore, the initial intensity is held at 55 kt.

A 12-hour motion estimate yields 085/4 kt, although satellite
animation seems to suggest that the cyclone is beginning to be
pulled northeastward.  Karina's movement will be at the mercy of
Tropical Storms Lowell and Marie through the entire forecast
period.  For the first 3-4 days, Karina is forecast to move
generally northeastward on the southern side of Lowell.  The big
difference from previous model cycles is that the guidance no
longer shows Karina being absorbed by Lowell.  Instead, Karina
slows down when it begins to feel the circulation of Marie.  The
track guidance has slowed down and shifted significantly to the
west by days 4 and 5, and the updated NHC track forecast has been
pulled southward at those times, but it is still on the northern
edge of the guidance envelope.

Karina's updated track keeps it over waters warmer than 26 degrees
Celsius for another 48 hours or so.  Vertical shear may increase a
little, but overall little change in intensity is forecast during
the next day or two.  Weakening should commence by 48 hours
when Karina moves over cooler water and into a drier air mass.
However, since the forecast track has been pulled southward, Karina
may not weaken quite as fast as previously thought, and the updated
NHC forecast keeps Karina as a tropical cyclone through day 4.


FORECAST POSITIONS AND MAX WINDS

INIT  22/0900Z 14.8N 135.8W   55 KT  65 MPH
 12H  22/1800Z 15.3N 135.3W   55 KT  65 MPH
 24H  23/0600Z 16.2N 134.6W   55 KT  65 MPH
 36H  23/1800Z 17.0N 133.6W   55 KT  65 MPH
 48H  24/0600Z 17.6N 132.2W   50 KT  60 MPH
 72H  25/0600Z 18.5N 129.5W   40 KT  45 MPH
 96H  26/0600Z 20.5N 129.5W   30 KT  35 MPH
120H  27/0600Z 22.5N 131.5W   25 KT  30 MPH...POST-TROP/REMNT LOW

$$
Forecaster Berg