{"id": "1213396781350649863", "title": "Tropical Cyclone Discussion", "adv_date": "2026-09-25T21:00:00Z", "msg": "220\nWTPZ42 KNHC 252055\nTCDEP2\n \nHurricane Polo Discussion Number  21\nNWS National Hurricane Center Miami FL       EP172026\n200 PM MST Fri Sep 25 2026\n \nA NOAA research aircraft has found that Polo remains a very \npowerful category 5 hurricane. The highest flight level winds \nmeasured by the aircraft were 165 kt in the northeast quadrant, and \nsince that measurement the central pressure has decreased a couple \nmillibars, to 913. An UAS launched from the plane measured a peak \nwind just above 200 kt at an altitude just below 500 m, which \ncorresponds to a 10 m wind of 150-155 kt based on an experimental \nwind reduction model. Taken all together, this data supports an \ninitial intensity of 155 kt. \n \nThe NOAA aircraft reported that there may be signs of an eyewall \nreplacement cycle beginning. Although this does not appear to be \nhaving an impact on the hurricane yet, it does highlight that \nfluctuations in the intensity of Polo are likely over the next 24 h \nwhile it remains over warm waters. After that, some weakening is \nexpected as Polo begins to move into a region with lower ocean heat \ncontent and the vertical wind shear increases slightly. However, it \nis expected to remain a powerful major hurricane through the \nweekend. The NHC intensity forecast is still near the upper-end of \nthe intensity guidance and is very similar to the previous advisory.\n\nOnly small adjustments were made to the official track forecast, \nwith the biggest change being that the anticipated forward motion \nfor Polo is slightly faster in this advisory. Polo is still \nexpected to turn gradually northwestward, then northward this \nweekend as it moves around the western side of a ridge centered \nover northern Mexico. Then early next week an upper-level trough \napproaching from the northwest will likely cause the hurricane to \nturn northeastward toward Baja California Sur and west-central \nMexico. The AI models, notably GDM and the experimental \nWeatherNext3, generally show a slightly faster motion than most of \nthe dynamical guidance, and the model spread has increased at 72 h \nand beyond. The forecast confidence is correspondingly lower with \nthis advisory. The NHC forecast is a blend of the consensus \nand continuity with the previous advisory. Based on the forecast \ntrack, watches could be required for portions of Baja California Sur \nas soon as tonight.\n\nDistant moisture from Hurricane Polo and Odalys will be transported\ninto the southwestern United States this weekend and early next\nweek, and may indirectly contribute to a heavy rainfall and flash\nflood threat in the region. See products issued by the Weather\nPrediction Center for more information.\n \n \nKey Messages:\n \n1. 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. Watches could be required as early as tonight for\nportions of the area.\n \n2. Heavy rainfall associated with Polo may begin to impact Baja\nCalifornia Sur late Sunday into Monday. This rainfall may produce\nlife-threatening flooding and mudslides, especially in areas of\nsteep terrain.\n \n \nFORECAST POSITIONS AND MAX WINDS\n \nINIT  25/2100Z 17.2N 109.2W  155 KT 180 MPH\n 12H  26/0600Z 17.4N 110.6W  150 KT 175 MPH\n 24H  26/1800Z 18.2N 112.1W  140 KT 160 MPH\n 36H  27/0600Z 19.6N 113.2W  125 KT 145 MPH\n 48H  27/1800Z 21.5N 113.7W  115 KT 130 MPH\n 60H  28/0600Z 23.4N 113.6W  100 KT 115 MPH\n 72H  28/1800Z 25.1N 112.8W   95 KT 110 MPH\n 96H  29/1800Z 28.5N 109.7W   60 KT  70 MPH...INLAND\n120H  30/1800Z 32.0N 105.5W   25 KT  30 MPH...POST-TROP/INLAND\n \n"}