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Tropical Storm Karina Discussion Number  11
NWS National Hurricane Center Miami FL       EP162020
800 AM PDT Tue Sep 15 2020
 
Karina has changed little in organization over the past several 
hours with a concentrated area of deep convection mostly over the 
southwestern portion of the circulation and over the estimated 
position of the low-level center. The initial intensity is kept at 
50 kt based on a blend of the latest Dvorak CI numbers from TAFB and 
SAB and the objective UW-CIMSS ADT.
 
Karina is now crossing the 26 isotherm, so it is unlikely that any 
further strengthening will occur. The cyclone is forecast to move 
over progressively cooler waters and into a drier, more stable 
atmosphere over the next couple of days. These conditions should 
induce a weakening trend soon, and the deep convection is expected 
to gradually wane during that time. Karina is forecast to become a 
convection-free remnant low by 60 h, or perhaps a little sooner. The 
latest NHC intensity forecast is in good agreement with the various 
guidance aids. 
 
The initial motion of the tropical storm is 310/09 kt, as it 
continues to move along the periphery of a mid-level ridge to its 
northeast. This general motion should continue while the system 
maintains convection. As the system becomes devoid of convection, a 
turn to the west and west-southwest is anticipated as the cyclone 
moves within the low-level flow.
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  15/1500Z 20.4N 121.1W   50 KT  60 MPH
 12H  16/0000Z 21.3N 122.2W   45 KT  50 MPH
 24H  16/1200Z 22.4N 123.9W   40 KT  45 MPH
 36H  17/0000Z 23.3N 125.2W   35 KT  40 MPH
 48H  17/1200Z 23.7N 126.2W   30 KT  35 MPH
 60H  18/0000Z 23.9N 127.3W   25 KT  30 MPH...POST-TROP/REMNT LOW
 72H  18/1200Z 23.5N 128.3W   25 KT  30 MPH...POST-TROP/REMNT LOW
 96H  19/1200Z 22.6N 130.7W   20 KT  25 MPH...POST-TROP/REMNT LOW
120H  20/1200Z...DISSIPATED
 
$$
Forecaster Latto
 
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