986 WTNT44 KNHC 140231 TCDAT4 Tropical Storm Karl Discussion Number 11 NWS National Hurricane Center Miami FL AL142022 1000 PM CDT Thu Oct 13 2022 Data from an Air Force Reserve Hurricane Hunter aircraft indicate that Karl has a tilted vertical structure, typical for a cyclone affected by shear. The low-level center remains on the northwestern edge of an area of deep convection, with an elevated center found by the plane slightly east of that location under the convective canopy. The highest reliable surface winds sampled by the SFMR instrument on board the aircraft were 34 kt in the southeastern quadrant, and dropsonde data indicate that the central pressure has fallen to 998 mb. Earlier satellite wind data suggest that some stronger winds were occurring to the south of where the aircraft measured the recent peak winds. Based on these data and the lack of much change in the appearance of Karl, its assumed that cyclone still has maximum surface winds of around 40 kt. Karl has been deviating to the east of the previous forecast track this evening, likely due to the ongoing downshear development of the deep convection, and the initial motion is 135/6 kt. The storm should turn southward by Friday and then south-southwestward by Friday night as the system reaches the periphery of a mid-level ridge over west-central Mexico. This south-southwestward motion is expected to continue until Karl dissipates over Mexico in a couple of days. The model guidance has once again shifted slightly east, likely due to the east-of-track initial position. The latest NHC track forecast was nudged eastward as a result. Based on the increasing possibility of impacts farther east along the southern Mexico coast, a Tropical Storm Warning was issued from Ciudad del Carmen to Sabancuy. Moderate west-northwesterly shear impacting Karl is expected to persist until landfall. Mid-level dry air intrusions are also forecast to continue for the next day or so. Therefore, strengthening is unlikely. The model guidance suggests that Karl should maintain its current intensity overnight, and perhaps weaken slightly before it reaches the coast of southern Mexico Friday night or early Saturday. Once inland, the cyclone should steadily weaken on Saturday and dissipate by Saturday night. Key Messages: 1. Heavy rainfall associated with 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. 2. Tropical storm conditions are expected to begin within a portion of the warning area in southern Mexico by late Friday. FORECAST POSITIONS AND MAX WINDS INIT 14/0300Z 20.6N 92.8W 40 KT 45 MPH 12H 14/1200Z 19.9N 92.6W 40 KT 45 MPH 24H 15/0000Z 19.0N 92.8W 35 KT 40 MPH 36H 15/1200Z 18.0N 93.4W 30 KT 35 MPH...INLAND 48H 16/0000Z...DISSIPATED $$ Forecaster Latto/Berg