{"id": "1222239545544081415", "title": "Tropical Cyclone Discussion", "adv_date": "2026-10-27T03:00:00Z", "msg": "262\nWTPZ42 KNHC 270231\nTCDEP2\n \nTropical Storm Vance Discussion Number  23\nNWS National Hurricane Center Miami FL       EP222026\n800 PM MST Mon Oct 26 2026\n \nThe structure of Vance has degraded significantly over the last \nseveral hours as the center of the cyclone has become separated from \nthe convection as seen on visible satellite imagery. Based on a \ncombination of the subjective and objective intensity estimates, the \ninitial intensity has been lowered to 45 kt. \n \nVance has continued to move slowly to the west, 275/4 kt. The \ntropical storm is expected to make a turn to west-northwest or \nnorthwest over the next 24 h due to a weak mid-level ridge to the \nnorth of the system. By Wednesday, a broad mid-level trough near the \nBaja California Peninsula should force Vance to turn more to the \nnorth. The current NHC track forecast remains in good agreement with \nthe most recent GDMI and HCCA models. There is still some model \nspread in the latter portion of the track forecast, however the \ncurrent track still favors a more slower storm motion overall. \n\nStrong westerly to southwesterly wind shear is expected to persist \nand increase through the forecast period. However, given the \npresence of warm water and sufficient atmospheric moisture, the \ncyclone is currently forecast to weaken only gradually over the next \nseveral days. The intensity forecast remains on the upper end of the \nguidance and brings Vance to a post-tropical cyclone around 72 \nhours, as the convection will likely be sheared off by the \naforementioned trough by that time. It should be noted that it is \npossible the system could degenerate into a remnant low sooner than \ncurrently forecast, however, GFS and ECMWF simulated satellite \nguidance indicates that intermittent convective bursts could still \noccur near the center during the next few days.\n \nKey Messages:\n \n1. Periods of heavy rainfall associated with Vance will impact \nportions of western Mexico during much of this week. This rainfall \nmay produce flooding and mudslides across southern Sinaloa, \nsouthwest Durango, and coastal sections of Nayarit and Jalisco, \nespecially in areas along steep terrain.\n \n2. Interests in southwest and west-central Mexico should \ncontinue to monitor Vance's progress.\n \n \nFORECAST POSITIONS AND MAX WINDS\n \nINIT  27/0300Z 15.5N 106.3W   45 KT  50 MPH\n 12H  27/1200Z 15.9N 107.1W   45 KT  50 MPH\n 24H  28/0000Z 17.2N 107.9W   40 KT  45 MPH\n 36H  28/1200Z 18.8N 108.3W   40 KT  45 MPH\n 48H  29/0000Z 20.5N 108.3W   40 KT  45 MPH\n 60H  29/1200Z 22.0N 108.1W   35 KT  40 MPH\n 72H  30/0000Z 23.5N 107.6W   30 KT  35 MPH...POST-TROP/REMNT LOW\n 96H  31/0000Z...DISSIPATED\n \n"}