{"id": "1212899462768951303", "title": "Tropical Cyclone Discussion", "adv_date": "2026-09-24T03:00:00Z", "msg": "183\nWTPZ42 KNHC 240245\nTCDEP2\n \nHurricane Polo Discussion Number  14\nNWS National Hurricane Center Miami FL       EP172026\n900 PM CST Wed Sep 23 2026\n \nThe changes to the satellite presentation of Polo this evening \nindicate the hurricane has significantly strengthened. The symmetric \neye has gradually cleared out and warmed, and it is now surrounded \nby a thick ring of very deep convection with cloud top temperatures \nof -75 to -80 deg C. The objective and subjective satellite \nintensity estimates have quickly increased this evening as a result, \nand the initial intensity is set at 140 kt, making Polo a category 5 \nhurricane once again.\n \nPolo has taken a slow north-northwestward jog this evening, but the \nlong-term motion remains northwestward (320/5 kt). The short-term \ntrack forecast has been nudged slightly northward to account for the \nnorthward jog. A mid-level ridge over Texas and northern Mexico is \nexpected to gradually build westward during the next couple of days, \nwhich should steer Polo to the northwest and west-northwest away \nfrom mainland Mexico through Friday night. Then, an upper-level \ntrough is forecast to approach the west coast of the United States \nthis weekend. This will weaken the steering ridge and cause Polo to \nturn toward the northwest and north later in the forecast period, \nbringing the center toward Baja California Sur. However, there is \nstill quite a bit of along- and cross-track spread regarding the \ndetails of this anticipated turn. The long-range portion of the \ntrack forecast remains close to the previous one, closely following \nthe HCCA and TVCN aids through 96 h.\n \nNow that Polo has completed an eyewall replacement cycle (ERC), some \nadditional near-term strengthening could occur with conducive \nenvironmental and oceanic conditions in place. The updated NHC \nforecast accounts for this potential and lies on the upper end of \nthe guidance. Of course, strong hurricanes like Polo can also be \nsusceptible to intensity fluctuations related to internal dynamic \nprocesses like ERCs that are difficult to predict. Regardless, there \nis high confidence that Polo will remain a powerful major hurricane \nfor the next few days. Vertical wind shear is forecast to increase \nover the hurricane in 48-72 h, and a somewhat faster rate of \nweakening is shown thereafter. Overall, the NHC intensity forecast \nfollows the multi-model trends and lies on the higher end of the \nenvelope for most of the period.\n \nThe government of Mexico has extended the Tropical Storm Warning\nwestward from Punta San Telmo to Manzanillo.\n \nKey Messages:\n \n1. Heavy rainfall associated with Polo will impact coastal portions\nof southwest Mexico through Thursday. This rainfall may produce\nlife-threatening flooding and mudslides, especially in areas of\nsteep terrain.\n \n2. Tropical storm conditions are expected to spread across portions\nof the coast within the warning area from Tecpan de Galeana to\nManzanillo tonight into early Thursday.\n \n \nFORECAST POSITIONS AND MAX WINDS\n \nINIT  24/0300Z 16.0N 102.4W  140 KT 160 MPH\n 12H  24/1200Z 16.5N 103.7W  150 KT 175 MPH\n 24H  25/0000Z 16.9N 105.6W  145 KT 165 MPH\n 36H  25/1200Z 17.1N 107.5W  140 KT 160 MPH\n 48H  26/0000Z 17.3N 109.4W  135 KT 155 MPH\n 60H  26/1200Z 17.9N 111.0W  130 KT 150 MPH\n 72H  27/0000Z 19.2N 112.2W  115 KT 130 MPH\n 96H  28/0000Z 22.5N 113.3W  100 KT 115 MPH\n120H  29/0000Z 25.5N 113.0W   80 KT  90 MPH\n \n"}