{"id": "1213183129601015815", "title": "Tropical Cyclone Discussion", "adv_date": "2026-09-25T03:00:00Z", "msg": "155\nWTPZ42 KNHC 250248\nTCDEP2\n \nHurricane Polo Discussion Number  18\nNWS National Hurricane Center Miami FL       EP172026\n800 PM MST Thu Sep 24 2026\n\nPowerful Polo continues to have an impressive presentation on \nsatellite imagery.  The eye is estimated to be around 20 n mi in \ndiameter and is embedded within a 180 n mi wide Central Dense \nOvercast of very cold cloud tops.  The upper-level outflow \npattern is quite symmetrical, indicative of weak vertical wind shear \nover the system.  The advisory intensity is held at 130 kt, in \nreasonable agreement with a subjective Dvorak estimate from TAFB and \nobjective estimates from UW-CIMSS.\n\nThe hurricane is now moving on a mainly westward track with an \ninitial motion estimated to be about 280/9 kt.  There is little \nchange to the track forecast philosophy from the previous advisory. \nPolo is currently being steered by the flow on the south \nside of a well-defined mid-tropospheric ridge that is building \nwestward over northern Mexico.  This steering regime should \ncontinue through Friday.  After that, a mid-latitude trough moving \neastward across the northeastern Pacific should prevent the ridge \nfrom building farther west, with Polo likely to recurve northward \nand northeastward around the western periphery of the ridge.  The \ntrack guidance is generally in agreement on this scenario, although \nthere are still notable differences in forward speed among the \nmodels in the 3-5 day time frame.  The official forecast is similar \nto the previous one, aside from showing a bit wider turn around the \nridge before nearing the Baja California Peninsula in around 96 \nhours.  This is a blend of the latest GDMI and HCCA solutions.\n\nPolo will continue to move over very warm waters and in a low \nvertical wind shear environment through Friday.  Given the conducive \nconditions, the hurricane could regain category 5 intensity soon.  \nAround 36 hours, a gradual weakening trend is expected to begin due \nto some increase in shear.  The official intensity forecast is on \nthe high side of the model guidance, and shows the system still \nnear major hurricane strength while it approaches the Baja \nCalifornia peninsula.  Rapid weakening is expected when the cyclone \ncrosses the peninsula and moves into mainland Mexico.\n \nIt should be noted that moisture from Hurricane Polo and Odalys\nwill be carried a long distance into the southwestern United States\nthis weekend and early next week, and may indirectly contribute to\na heavy rainfall and flash flood threat in the region. See products\nissued by the Weather Prediction Center for more information.\n \n \nKey Messages:\n\n1. Heavy rainfall associated with Polo will impact coastal portions \nof southwest Mexico through the evening.  This rainfall may produce \nlife-threatening flooding and mudslides, especially in areas of \nsteep terrain.\n \n2. Wind gusts to tropical storm force may still occur along \nportions of the southwestern coast of Mexico this evening.\n \n3. Polo is forecast to approach the Baja California Peninsula early\nnext week as a hurricane.  Interests there should closely monitor\nthe latest updates and ensure that they have their preparedness\nplan in place.\n \n \nFORECAST POSITIONS AND MAX WINDS\n \nINIT  25/0300Z 17.1N 106.5W  130 KT 150 MPH\n 12H  25/1200Z 17.4N 108.1W  140 KT 160 MPH\n 24H  26/0000Z 17.5N 110.0W  130 KT 150 MPH\n 36H  26/1200Z 18.0N 111.6W  120 KT 140 MPH\n 48H  27/0000Z 19.2N 112.9W  115 KT 130 MPH\n 60H  27/1200Z 20.8N 113.7W  110 KT 125 MPH\n 72H  28/0000Z 22.6N 114.0W  105 KT 120 MPH\n 96H  29/0000Z 25.7N 112.5W   95 KT 110 MPH\n120H  30/0000Z 27.3N 109.8W   60 KT  70 MPH...INLAND\n \n"}