000 WTPZ43 KNHC 211432 TCDEP3 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