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Tropical Storm Kevin Discussion Number  18
NWS National Hurricane Center Miami FL       EP112021
200 PM PDT Wed Aug 11 2021
 
Satellite imagery this afternoon shows that Kevin continues to
have a large circulation, but that the deep convection is
well-removed from the tropical storm's center. A blend of the
Dvorak classifications from SAB and TAFB suggest that the system
remains with an intensity of 40 kt, which is also supported by
1723Z SATCON estimate of 38 kt.
 
Kevin's short-term movement has been a bit more westward, perhaps 
due to pulling by the remaining deep convection restricted to its 
southwestern quadrant. The longer-term initial motion is estimated 
as 290 degrees at 9 kt.  The tropical storm is primarily being 
steered along the southwestern periphery of a deep tropospheric 
ridge.  However, as the deep convection ceases completely in a day 
or two, the system will increasingly be steered by the lower 
tropospheric flow.  A motion toward the west-northwest or northwest 
at a slightly faster forward speed is anticipated until dissipation. 
 The official track forecast is based upon the HFIP Corrected 
Consensus Approach (HCCA), which is midway between the GFS and ECMWF 
global model solutions but substantially faster than the mesoscale 
hurricane model output. This new forecast is slightly westward of 
the previous advisory, due to the somewhat more westward position at 
the initial time.
 
The tropical storm has already moved across the 26C SST isotherm and 
is moving toward even cooler water, drier air, and a more stable 
atmosphere.  Additionally, Kevin is being affected by moderate NE 
tropospheric vertical wind shear.  The large system should gradually 
weaken under these increasingly hostile conditions and it's likely 
that Kevin will become a remnant low by late Thursday. The official 
intensity forecast is based upon the IVCN statistical scheme and is 
nearly the same as the previous advisory.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  11/2100Z 21.1N 117.8W   40 KT  45 MPH
 12H  12/0600Z 22.2N 119.3W   35 KT  40 MPH
 24H  12/1800Z 23.4N 121.6W   30 KT  35 MPH
 36H  13/0600Z 24.7N 124.0W   25 KT  30 MPH...POST-TROP/REMNT LOW
 48H  13/1800Z 26.2N 126.3W   25 KT  30 MPH...POST-TROP/REMNT LOW
 60H  14/0600Z 27.9N 128.2W   20 KT  25 MPH...POST-TROP/REMNT LOW
 72H  14/1800Z 29.5N 129.4W   20 KT  25 MPH...POST-TROP/REMNT LOW
 96H  15/1800Z...DISSIPATED
 
$$
Forecaster Landsea
 
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