{"id": "1222455730020843527", "title": "Tropical Cyclone Discussion", "adv_date": "2026-10-27T21:00:00Z", "msg": "321\nWTPZ42 KNHC 272051\nTCDEP2\n \nTropical Storm Vance Discussion Number  26\nNWS National Hurricane Center Miami FL       EP222026\n200 PM MST Tue Oct 27 2026\n \nSignificant westerly wind shear and a dry mid-level environment are \nsubstantially impacting Vance this afternoon. Deep convection \nremains disorganized and displaced from the fully exposed low-level \ncenter, with the deepest thunderstorms located 50-100 mi east of the \ncenter. Recent objective and subjective satellite intensity \nestimates range from 26-36 kt. However, a recent METOP-B \nscatterometer pass indicated tropical-storm-force winds northeast \nand southeast of the center, and this was instrumental in \ndetermining the wind radii for this advisory. Based on the data, \nthe intensity is maintained at 35 kt for this advisory.\n \nVance is moving northwestward at 305/08 kt, guided by a low-level\nridge centered over the south-central United States. A gradual turn\ntoward the north is forecast over the next couple of days as a\nstrong mid-level trough moves down the U.S. West Coast. This\nsteering pattern would bring Vance toward the entrance of the Gulf\nof California by Thursday. The latest NHC track forecast has been\nshifted slightly to the left and lies near the latest HFIP corrected\nconsensus aid (HCCA).\n \nDespite moving over warm sea surface temperatures of 29-30 C over\nthe next couple of days, an increase in already significant wind\nshear may offset any potential strengthening. However, intensity\nguidance remains mixed, so the NHC forecast follows a consensus\napproach and calls for no net change through midweek, although some\nfluctuations are possible during this period. Vance is already\nstruggling to maintain organized deep convection near its center,\nand simulated satellite imagery from the GFS and ECMWF suggests that\norganized convection could become difficult to sustain by early\nThursday. Therefore, the latest NHC forecast calls for Vance to\nbecome post-tropical by 36 h and degenerate into a remnant low by 60\nh, around the time of its closest approach to west-central Mexico.\nIf Vance is unable to sustain organized convection closer to its\ncenter, the transition to a post-tropical cyclone could occur even\nsooner than currently forecast. Given this forecast, the threat of\ntropical storm conditions over land remains low at this time.\n \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 central and southern\nSinaloa, western Durango, and northwestern Nayari, especially in\nareas along steep terrain.\n \n2. Interests along the southwestern and west-central coasts of\nMexico and the southern Baja California Peninsula should monitor the\nprogress of Vance.\n \n \nFORECAST POSITIONS AND MAX WINDS\n \nINIT  27/2100Z 17.2N 108.3W   35 KT  40 MPH\n 12H  28/0600Z 18.1N 108.7W   35 KT  40 MPH\n 24H  28/1800Z 19.7N 108.9W   35 KT  40 MPH\n 36H  29/0600Z 21.2N 108.7W   35 KT  40 MPH...POST-TROPICAL\n 48H  29/1800Z 22.9N 108.3W   35 KT  40 MPH...POST-TROPICAL\n 60H  30/0600Z 24.7N 107.9W   30 KT  35 MPH...POST-TROP/REMNT LOW\n 72H  30/1800Z...DISSIPATED\n \n"}