####018002385####
WTPZ43 KNHC 210232

TCDEP3

 

Tropical Storm Kenneth Discussion Number   7

NWS National Hurricane Center Miami FL       EP132023

800 PM PDT Wed Sep 20 2023

 

It appears that southerly mid-level shear has set in over Kenneth 

during the day, and the surface center is now located on the 

southern side of the ongoing convective mass.  Dvorak final-T 

numbers are a consensus 3.0 from TAFB and SAB, so the initial 

intensity remains 45 kt.



The shear appears to have pulled Kenneth's center farther to the 

north, and as a result, the storm has turned northwestward with an 

initial motion of 310/10 kt.  A turn toward the north-northwest and 

north is expected over the next 36 hours as Kenneth moves around 

the western periphery of the subtropical ridge.  Partly because of 

the required adjustment of the initial position, the track guidance 

has shifted significantly to the north and east on this cycle.  The 

new NHC track forecast lies very close to the GFS, ECMWF, TVCE, and 

HCCA aids, particularly during the first 36 hours of the forecast, 

and is as much as 30-40 n mi to the right of the previous 

prediction.



As is often the case, the mid-level shear affecting the cyclone was 

not foreseen, as nearly all shear diagnostics show that the shear in 

a deeper layer of the atmosphere is currently very low.  That said, 

even the deep-layer shear is forecast to increase to 

moderate-to-strong levels in the next 12-24 hours.  Simultaneously, 

Kenneth will be moving over increasingly cooler waters that are less 

than 26 degrees Celsius.  Therefore, weakening is expected to begin 

by 24 hours, and strong shear and a drier, more stable atmosphere 

should cause Kenneth to degenerate into a remnant low by late 

Friday.  The remnant low could hang around for a few days, opening 

up into a trough by Sunday.

 

 

FORECAST POSITIONS AND MAX WINDS

 

INIT  21/0300Z 16.9N 125.2W   45 KT  50 MPH

 12H  21/1200Z 17.6N 126.0W   45 KT  50 MPH

 24H  22/0000Z 19.0N 126.8W   40 KT  45 MPH

 36H  22/1200Z 20.7N 126.9W   35 KT  40 MPH

 48H  23/0000Z 22.1N 126.8W   30 KT  35 MPH...POST-TROP/REMNT LOW

 60H  23/1200Z 23.1N 126.8W   25 KT  30 MPH...POST-TROP/REMNT LOW

 72H  24/0000Z 23.8N 127.2W   25 KT  30 MPH...POST-TROP/REMNT LOW

 96H  25/0000Z...DISSIPATED

 

$$

Forecaster Berg