Tropical Cyclone Discussion
155 WTPZ42 KNHC 250248 TCDEP2 Hurricane Polo Discussion Number 18 NWS National Hurricane Center Miami FL EP172026 800 PM MST Thu Sep 24 2026 Powerful Polo continues to have an impressive presentation on satellite imagery. The eye is estimated to be around 20 n mi in diameter and is embedded within a 180 n mi wide Central Dense Overcast of very cold cloud tops. The upper-level outflow pattern is quite symmetrical, indicative of weak vertical wind shear over the system. The advisory intensity is held at 130 kt, in reasonable agreement with a subjective Dvorak estimate from TAFB and objective estimates from UW-CIMSS. The hurricane is now moving on a mainly westward track with an initial motion estimated to be about 280/9 kt. There is little change to the track forecast philosophy from the previous advisory. Polo is currently being steered by the flow on the south side of a well-defined mid-tropospheric ridge that is building westward over northern Mexico. This steering regime should continue through Friday. After that, a mid-latitude trough moving eastward across the northeastern Pacific should prevent the ridge from building farther west, with Polo likely to recurve northward and northeastward around the western periphery of the ridge. The track guidance is generally in agreement on this scenario, although there are still notable differences in forward speed among the models in the 3-5 day time frame. The official forecast is similar to the previous one, aside from showing a bit wider turn around the ridge before nearing the Baja California Peninsula in around 96 hours. This is a blend of the latest GDMI and HCCA solutions. Polo will continue to move over very warm waters and in a low vertical wind shear environment through Friday. Given the conducive conditions, the hurricane could regain category 5 intensity soon. Around 36 hours, a gradual weakening trend is expected to begin due to some increase in shear. The official intensity forecast is on the high side of the model guidance, and shows the system still near major hurricane strength while it approaches the Baja California peninsula. Rapid weakening is expected when the cyclone crosses the peninsula and moves into mainland Mexico. It should be noted that moisture from Hurricane Polo and Odalys will be carried a long distance 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. Heavy rainfall associated with Polo will impact coastal portions of southwest Mexico through the evening. This rainfall may produce life-threatening flooding and mudslides, especially in areas of steep terrain. 2. Wind gusts to tropical storm force may still occur along portions of the southwestern coast of Mexico this evening. 3. 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. FORECAST POSITIONS AND MAX WINDS INIT 25/0300Z 17.1N 106.5W 130 KT 150 MPH 12H 25/1200Z 17.4N 108.1W 140 KT 160 MPH 24H 26/0000Z 17.5N 110.0W 130 KT 150 MPH 36H 26/1200Z 18.0N 111.6W 120 KT 140 MPH 48H 27/0000Z 19.2N 112.9W 115 KT 130 MPH 60H 27/1200Z 20.8N 113.7W 110 KT 125 MPH 72H 28/0000Z 22.6N 114.0W 105 KT 120 MPH 96H 29/0000Z 25.7N 112.5W 95 KT 110 MPH 120H 30/0000Z 27.3N 109.8W 60 KT 70 MPH...INLAND