{"id": "1221745478961004546", "title": "Tropical Cyclone Discussion", "adv_date": "2026-10-25T09:00:00Z", "msg": "704\nWTPZ42 KNHC 250838\nTCDEP2\n \nHurricane Vance Discussion Number  16\nNWS National Hurricane Center Miami FL       EP222026\n300 AM CST Sun Oct 25 2026\n \nVance's convective structure continues to be impacted by \nsouthwesterly wind shear. Showers and thunderstorms have become less \norganized, and most of the convection is now occurring in the \nnorthern semi-circle. The latest subjective and objective intensity \nestimates range from 62 to 77 kt. Given the ragged satellite \nappearance, the initial intensity is lowered to 75 kt for this \nadvisory, and that could be generous.\n\nThe system is moving north-northwestward at 340/04 kt, steered \nbetween a trough over the western United States and the western \nperiphery of a mid-level ridge over Mexico. Vance remains in weak \nsteering currents, a slow, generally north-northwestward to \nnorthwestward motion is expected over the next few days. There \nremain some along-track differences in the forward speed of the \nsystem toward the end of the forecast period, which will be \ndependent on the vertical depth of the vortex at that \ntime. The latest NHC track forecast has been shifted westward once \nagain, but it remains on the eastern edge of the guidance envelope \ndue to continuity constraints, with the HCCA and GDMI aids lying to \nthe west of the current track.\n\nVance will continue to encounter moderate southwesterly wind shear \nand remains in the wake of an abundance of recent cyclones that have \nmoved over this area off the southwestern coast of Mexico over the \npast month or so. While oceanic heat content may increase slightly, \nmid-level dry air is forecast to entrain into the circulation, and \nshear should increase even further. This will induce a steadier rate \nof weakening. The NHC intensity forecast trends toward the latest \nHCCA guidance and shows an overall faster rate of weakening than the \nprevious advisory. By the end of the forecast period, increasing \nshear and dry air should take their toll on the convection \norganization of Vance. Global models show the system may struggle to \nproduce organized deep convection by Day 5, and the latest forecast \nnow shows Vance becoming a post-tropical cyclone at that time.\n \n \nKey Messages:\n \n1. Due to the large uncertainties in both the track and intensity \nforecasts, it is too early to determine what, if any, wind and storm \nsurge impacts Vance could bring to the coast of Mexico. Interests in \nsouthwestern Mexico should continue to monitor the progress of \nVance.\n \n2. Periods of heavy rainfall associated with slow-moving Hurricane \nVance will impact the western coast of Mexico from Michoac\u00e1n to \nJalisco during much of this week. This rainfall may produce flooding \nand mudslides across Colima and western portions of Michoac\u00e1n and \nJalisco, especially in areas along steep terrain.\n \n \nFORECAST POSITIONS AND MAX WINDS\n \nINIT  25/0900Z 14.3N 103.4W   75 KT  85 MPH\n 12H  25/1800Z 14.8N 103.8W   70 KT  80 MPH\n 24H  26/0600Z 15.4N 104.4W   70 KT  80 MPH\n 36H  26/1800Z 15.8N 104.9W   65 KT  75 MPH\n 48H  27/0600Z 16.3N 105.5W   60 KT  70 MPH\n 60H  27/1800Z 17.1N 105.8W   55 KT  65 MPH\n 72H  28/0600Z 17.9N 106.0W   45 KT  50 MPH\n 96H  29/0600Z 19.3N 106.5W   40 KT  45 MPH\n120H  30/0600Z 20.7N 106.9W   35 KT  40 MPH...POST-TROPICAL\n \n"}