915 WTNT44 KNHC 131443 TCDAT4 Tropical Storm Karl Discussion Number 9 NWS National Hurricane Center Miami FL AL142022 1000 AM CDT Thu Oct 13 2022 A burst of deep convection has developed over the southeastern portion of Karl's circulation since the previous advisory. Data from an Air Force Reserve reconnaissance aircraft and NOAA buoy 42055 indicate that the low-level center of the tropical cyclone is located near the northeastern edge of that convection due to northwesterly vertical wind shear. Although the aircraft has only measured flight-level and SFMR winds to support an intensity of around 40 kt, the advisory wind speed is maintained at 45 kt due to the recent increase in convection. Also, this gives the plane more time to fully examine the cyclone, as it is possible the strongest winds have yet to be sampled. Continued northwesterly shear and the entrainment of dry mid-level air are likely to cause some weakening over the next day or so, but Karl is forecast to be a tropical storm when it nears the coast of Mexico. After landfall, rapid weakening and dissipation of the low-level circulation is expected as the cyclone moves over the mountainous terrain of southern Mexico. Fixes from the aircraft show that Karl has finally begun its anticipated south-southeastward turn, and the initial motion estimate is 155/4 kt. A mid-level ridge to the northwest of Karl is expected to steer the storm south-southeastward through tonight. A southward to south-southwestward motion is forecast on Friday which should bring the center of Karl to the Bay of Campeche coast Friday night or Saturday. The guidance envelope has moved slightly eastward this cycle, and the NHC track forecast has been adjusted in that direction. There is still some spread in the models as to how fast Karl will move southward, which results in some timing differences regarding landfall in Mexico. The official forecast is close to the GFEX and the other consensus aids to account for that. Based on the latest forecast, the government of Mexico has issued a Tropical Storm Warning for a portion of the coast of the Bay of Campeche. Key Messages: 1. Heavy rainfall associated with Karl could produce flash flooding, with mudslides in areas of higher terrain, across portions of Veracruz, Tabasco, Chiapas, and Oaxaca states in Mexico. 2. Tropical storm conditions are expected to begin within a portion of the warning area in Mexico by late Friday. FORECAST POSITIONS AND MAX WINDS INIT 13/1500Z 21.7N 93.9W 45 KT 50 MPH 12H 14/0000Z 21.0N 93.6W 40 KT 45 MPH 24H 14/1200Z 20.0N 93.3W 40 KT 45 MPH 36H 15/0000Z 19.1N 93.4W 40 KT 45 MPH 48H 15/1200Z 18.0N 94.3W 35 KT 40 MPH...INLAND 60H 16/0000Z 17.0N 95.0W 25 KT 30 MPH...POST-TROP/REMNT LOW 72H 16/1200Z...DISSIPATED $$ Forecaster Brown