WTNT44 KNHC 150847

Post-Tropical Cyclone Karl Discussion Number 16
NWS National Hurricane Center Miami FL AL142022
400 AM CDT Sat Oct 15 2022

Moderate to strong vertical wind shear and relatively low mid-level humidities have continued to take a toll on Karl. Satellite data and radar imagery from Mexico indicate that the cyclone has not produced any organized deep convection since around midday yesterday, and it is very unlikely any will return this morning. Therefore, Karl has become a remnant low and this will be the last NHC advisory on this system. The radar imagery has revealed a persistent area of showers and thunderstorms with heavy rainfall well south of Karl's center that appears to be related to upslope flow against the mountainous terrain of southern Mexico. Within this cluster of convection, a significant amount of lightning has been noted in the GOES Lightning Mapper (GLM) data overnight. Karl's remnants could still produce flash flooding and mudslides over portions of southern Mexico through this weekend.

The initial intensity has been reduced to 25 kt, which is a blend of Dvorak T- and CI-numbers from TAFB and SAB. The global models indicate that the remnant low will continue to spin down today, and the official forecast calls for it to become a trough of low pressure by tonight when it moves inland over southern Mexico.

The low is currently moving southwestward at about 4 kt, and a southwestward to west-southwestward motion should continue until dissipation occurs. This motion should bring the center of the cyclone along the southern coast of the Bay of Campeche this morning, and inland by later today.

This is the last NHC advisory on this system. For additional information on heavy rainfall and flooding, please see products issued by your national meteorological service.

Key Messages:

1. Heavy rainfall associated with the remnants of Karl could produce instances of flash flooding, with mudslides in areas of higher terrain, across portions of Veracruz, Tabasco, Chiapas and Oaxaca states in Mexico.


INIT 15/0900Z 18.6N 93.0W 25 KT 30 MPH...POST-TROPICAL 12H 15/1800Z 18.3N 93.9W 20 KT 25 MPH...POST-TROP/REMNT LOW 24H 16/0600Z...DISSIPATED

$$ Forecaster Brown