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| #1111713 (Received by flhurricane at: 10:36 PM 12.Oct.2022) TCDAT4 Tropical Storm Karl Discussion Number 7 NWS National Hurricane Center Miami FL AL142022 1000 PM CDT Wed Oct 12 2022 Shear is having a greater influence on Karl this evening, with GOES-16 proxy-visible satellite imagery showing the low-level center now exposed to the northwest of a strong cluster of deep convection. An Air Force Reserve Hurricane Hunter aircraft investigating the storm found a similar peak 850-mb flight-level wind as earlier today (57 kt), but the SFMR readings have not been as high. However, the strongest winds from earlier were directly east of the center, and the current aircraft has not sampled that area of the storm. Plus, the central pressure was found to have fallen to 1000 mb during this mission. Therefore, the initial intensity remains 50 kt. The center does not look like it's moved very much during the past few hours, and that is confirmed by the aircraft fixes. A mid-level high located over west-central Mexico and a large-amplitude mid-latitude trough over the United States are expected to impart northerly or northwesterly flow over Karl on Thursday, which should push the cyclone southward into the Bay of Campeche during the next couple of days. The track guidance has again shifted eastward a bit on this cycle, but most of that is related to Karl's adjusted initial position and not with any particular change in forecast reasoning. The updated NHC track is nudged eastward from the previous prediction, especially during the first 48 hours, and it shows Karl reaching the coasts of Tabasco or Veracruz states in Mexico by Saturday morning. Deep-layer shear has increased to near 20 kt out of the west, and that magnitude is unlikely to decrease during the next few days. Even though ocean temperatures are about 28 degrees Celsius, a combination of the continued shear and surrounding dry mid-level air is expected to cause a gradual weakening trend while Karl approaches the Bay of Campeche coast of Mexico. The NHC intensity forecast lies between the aggressive statistical-dynamical guidance (which show a little bit of strengthening) and the regional hurricane models and consensus aids (which show almost immediate weakening). Fast weakening is expected after Karl reaches land, and the system is forecast to degenerate into a remnant low, or even dissipate, by late Saturday. 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, and Chiapas states in Mexico. 2. Tropical storm conditions are possible in the watch area in Mexico beginning late Friday. FORECAST POSITIONS AND MAX WINDS INIT 13/0300Z 22.4N 94.3W 50 KT 60 MPH 12H 13/1200Z 22.0N 94.0W 50 KT 60 MPH 24H 14/0000Z 21.1N 93.7W 50 KT 60 MPH 36H 14/1200Z 20.1N 93.5W 45 KT 50 MPH 48H 15/0000Z 19.1N 93.6W 40 KT 45 MPH 60H 15/1200Z 18.1N 94.2W 40 KT 45 MPH...INLAND 72H 16/0000Z 16.9N 94.7W 25 KT 30 MPH...POST-TROP/REMNT LOW 96H 17/0000Z...DISSIPATED $$ Forecaster Berg |
