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Tropical Storm Kevin Forecast Discussion Number 18
2021-08-11 22:55:06| National Hurricane Center (East Pacific)
Issued at 200 PM PDT Wed Aug 11 2021 000 WTPZ41 KNHC 112054 TCDEP1 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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