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Hurricane Kenneth Discussion Number  13
NWS National Hurricane Center Miami FL       EP132017
800 AM PDT Mon Aug 21 2017

Kenneth continues to have an impressive structure in satellite
images.  The eye of the hurricane remains distinct, and the
convective pattern is symmetric around the center.  The cloud
tops in the eyewall, however, are not quite as cold as they were
overnight, which resulted in a decrease of the 1200 UTC Dvorak
final-T numbers from TAFB and SAB.  Based on an average of the final
T- and CI-numbers from TAFB/SAB and ADT values from CIMSS at the
University of Wisconsin, the initial wind speed is lowered a
little, to 110 kt.

Kenneth has likely reached its peak intensity as it will be
crossing the 26 deg C isotherm later today.  In addition, the
hurricane will be moving into a progressively drier air mass.
These unfavorable thermodynamics combined with a significant
increase in southerly shear beginning in about 2 days should cause
Kenneth to weaken at a steady or rapid pace.  The system is forecast
to become a post-tropical cyclone in about 3 days when the shear is
expected to increase to near 30 kt while Kenneth is over SSTs below
23 deg C.  These conditions should cause the associated convection
to dissipate or be sheared away from the circulation.  The NHC
intensity forecast generally follows the IVCN and HCCA consensus
models.

The major hurricane is moving west-northwestward at 9 kt steered by
a mid-level ridge to its northeast.  The system is forecast to turn
to the northwest later today, followed by a north-northwestward
motion by late Tuesday as Kenneth moves into a pronounced weakness
caused by a cut-off low near the California coast.  The models are
in fairly good agreement, and only minor changes were made to the
previous NHC track forecast.  This forecast lies close to the
various consensus aids.

FORECAST POSITIONS AND MAX WINDS

INIT  21/1500Z 17.9N 130.9W  110 KT 125 MPH
 12H  22/0000Z 18.9N 132.0W  105 KT 120 MPH
 24H  22/1200Z 20.4N 133.1W   90 KT 105 MPH
 36H  23/0000Z 22.2N 134.0W   70 KT  80 MPH
 48H  23/1200Z 24.1N 134.9W   60 KT  70 MPH
 72H  24/1200Z 27.4N 136.0W   45 KT  50 MPH...POST-TROPICAL
 96H  25/1200Z 29.6N 136.8W   35 KT  40 MPH...POST-TROPICAL
120H  26/1200Z 31.0N 138.0W   25 KT  30 MPH...POST-TROP/REMNT LOW

$$
Forecaster Cangialosi

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