Tropical Cyclone Discussion
220 WTPZ42 KNHC 252055 TCDEP2 Hurricane Polo Discussion Number 21 NWS National Hurricane Center Miami FL EP172026 200 PM MST Fri Sep 25 2026 A NOAA research aircraft has found that Polo remains a very powerful category 5 hurricane. The highest flight level winds measured by the aircraft were 165 kt in the northeast quadrant, and since that measurement the central pressure has decreased a couple millibars, to 913. An UAS launched from the plane measured a peak wind just above 200 kt at an altitude just below 500 m, which corresponds to a 10 m wind of 150-155 kt based on an experimental wind reduction model. Taken all together, this data supports an initial intensity of 155 kt. The NOAA aircraft reported that there may be signs of an eyewall replacement cycle beginning. Although this does not appear to be having an impact on the hurricane yet, it does highlight that fluctuations in the intensity of Polo are likely over the next 24 h while it remains over warm waters. After that, some weakening is expected as Polo begins to move into a region with lower ocean heat content and the vertical wind shear increases slightly. However, it is expected to remain a powerful major hurricane through the weekend. The NHC intensity forecast is still near the upper-end of the intensity guidance and is very similar to the previous advisory. Only small adjustments were made to the official track forecast, with the biggest change being that the anticipated forward motion for Polo is slightly faster in this advisory. Polo is still expected to turn gradually northwestward, then northward this weekend as it moves around the western side of a ridge centered over northern Mexico. Then early next week an upper-level trough approaching from the northwest will likely cause the hurricane to turn northeastward toward Baja California Sur and west-central Mexico. The AI models, notably GDM and the experimental WeatherNext3, generally show a slightly faster motion than most of the dynamical guidance, and the model spread has increased at 72 h and beyond. The forecast confidence is correspondingly lower with this advisory. The NHC forecast is a blend of the consensus and continuity with the previous advisory. Based on the forecast track, watches could be required for portions of Baja California Sur as soon as tonight. Distant moisture from Hurricane Polo and Odalys will be transported into the southwestern United States this weekend and early next week, and may indirectly contribute to a heavy rainfall and flash flood threat in the region. See products issued by the Weather Prediction Center for more information. Key Messages: 1. Polo is forecast to approach the Baja California Peninsula early next week as a hurricane. Interests there should closely monitor the latest updates and ensure that they have their preparedness plan in place. Watches could be required as early as tonight for portions of the area. 2. Heavy rainfall associated with Polo may begin to impact Baja California Sur late Sunday into Monday. This rainfall may produce life-threatening flooding and mudslides, especially in areas of steep terrain. FORECAST POSITIONS AND MAX WINDS INIT 25/2100Z 17.2N 109.2W 155 KT 180 MPH 12H 26/0600Z 17.4N 110.6W 150 KT 175 MPH 24H 26/1800Z 18.2N 112.1W 140 KT 160 MPH 36H 27/0600Z 19.6N 113.2W 125 KT 145 MPH 48H 27/1800Z 21.5N 113.7W 115 KT 130 MPH 60H 28/0600Z 23.4N 113.6W 100 KT 115 MPH 72H 28/1800Z 25.1N 112.8W 95 KT 110 MPH 96H 29/1800Z 28.5N 109.7W 60 KT 70 MPH...INLAND 120H 30/1800Z 32.0N 105.5W 25 KT 30 MPH...POST-TROP/INLAND