{"id": "1185085113885655042", "title": "Tropical Cyclone Discussion", "adv_date": "2026-06-17T21:00:00Z", "msg": "824\nWTNT41 KNHC 172054\nTCDAT1\n \nTropical Storm Arthur Discussion Number   7\nNWS National Hurricane Center Miami FL       AL012026\n400 PM CDT Wed Jun 17 2026\n \nThe center of Arthur appears to have moved inland over Matagorda\nCounty, Texas, early this afternoon based on visible satellite\nimages and surface observations. However, the circulation center has\nbecome more diffuse and less defined over the past couple hours,\nmaking it difficult to track with much confidence. A large area of\ndeep convection persists over the northwestern Gulf of America, but\nstrong westerly shear has displaced it even farther from the center.\nMarine observations and data from the NOAA Hurricane Hunters show\ntropical-storm-force winds are still ongoing within this convection\nwell to the east and southeast of the center. Based on a blend of\nthe aircraft data and available surface observations, the initial\nintensity is held at 40 kt.\n \nThe low-level mean center has deviated more northward than expected \ntoday, and the long-term motion estimate is north-northeastward at \nabout 6 kt. Most models suggest the circulation center will \ndissipate within the next 6-12 h, but a continued motion toward the \nnorth-northeast is forecast for Arthur or its low-level remnants \nthrough tonight. This updated track forecast has shifted left \n(farther inland) due to the center relocation this afternoon. \nHowever, this is of little consequence as the greatest impacts from \nArthur are still being felt well to the east of its center.\n \nNow that the center of Arthur is inland, weakening is expected\nwhile it contends with strong westerly shear and some drier\nmid-level air infiltrating from the west. Model-simulated satellite\nimagery from the GFS and ECMWF suggest the associated convection\nshould mostly collapse tonight. The 12-h forecast point shows\nremnant low status, but it could just as likely dissipate before\nthat time. The ECMWF and Canadian models still suggest a potential\nfor low pressure development over the western Atlantic late this\nweek or this weekend as remnant vorticity from Arthur emerges off\nthe Southeast U.S. coast. However, it is unclear how tropical in\nnature this system would be if it were to develop, so we will\ncontinue to monitor model trends.\n \nHeavy rainfall and life-threatening flash flooding remain the \nprimary hazard, and it is stressed that this threat extends well \naway from the center and will persist even after Arthur dissipates. \nThere is also an increased tornado threat for portions of the \nsoutheastern U.S. through Thursday.\n \n \nKEY MESSAGES:\n \n1. Potentially life-threatening flash flooding and urban flooding\nare likely through Friday across southern Louisiana, southern\nMississippi, southern Alabama, southwestern Georgia, and the Florida\nPanhandle. Scattered minor river flooding is expected, with the\npotential for isolated moderate to major river flooding. Ongoing\nheavy rainfall could prolong the flood threat through the weekend.\n \n2. Tropical-storm-force winds, especially in gusts, are expected\nalong the Upper Texas and Louisiana coasts during the next few\nhours where a Tropical Storm Warning is in effect.\n \n3. Minor to moderate coastal flooding is expected along portions of\nthe Upper Texas and Louisiana coastlines today.\n \n \nFORECAST POSITIONS AND MAX WINDS\n \nINIT  17/2100Z 28.9N  96.1W   40 KT  45 MPH...INLAND\n 12H  18/0600Z 30.8N  94.6W   30 KT  35 MPH...POST-TROP/REMNT LOW\n 24H  18/1800Z...DISSIPATED\n \n"}