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TROPICAL STORM KARL DISCUSSION NUMBER  43
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL122016
1100 PM AST SAT SEP 24 2016

Karl continues to produce a large area of cold-topped convection
to the northeast of the center.  However, data from the NOAA P-3,
NOAA G-IV, and the NASA/NOAA Global Hawk aircraft indicate that the
circulation is losing definition as the cyclone accelerates toward
the northeast.  The initial intensity of 55 kt is based on a
combination of dropsonde, flight level, and SFMR winds from the
three planes, and the central pressure of 992 mb is based on data
from a Global Hawk dropsonde.  While Karl is expected to become
post tropical by 24 hours, it should intensify to a hurricane-force
system as it does so, and this is shown in the intensity forecast.
By 36 hours, the system should be absorbed into a larger
extratropical low to its northwest.

The initial motion estimate is now 055/25.  Karl should continue to
accelerate on a general northeastward heading ahead of a broad
deep-layer trough until the cyclone is absorbed, and the forward
speed is expected to be near 50 kt by 24 hours.  The new NHC track
forecast is an update of the previous one and remains near the
middle of the tightly packed guidance envelope.


FORECAST POSITIONS AND MAX WINDS

INIT  25/0300Z 35.0N  58.0W   55 KT  65 MPH
 12H  25/1200Z 38.2N  51.3W   60 KT  70 MPH
 24H  26/0000Z 44.6N  41.5W   70 KT  80 MPH...POST-TROPICAL
 36H  26/1200Z...ABSORBED BY LARGER EXTRATROPICAL LOW

$$
Forecaster Beven

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