Issued at 900 AM CST Thu Sep 24 2026
000 WTPZ42 KNHC 241440 TCDEP2 Hurricane Polo Discussion Number 16 NWS National Hurricane Center Miami FL EP172026 900 AM CST Thu Sep 24 2026 Satellite imagery shows that while Polo remains a powerful hurricane, there have been some structural changes during the past few hours. First, an AMSR3 overpass a few hours ago showed a new outer eyewall was forming, indicating that the hurricane is about to begin another eyewall replacement cycle. Second, while the eye and the central convective features remain well defined, there is now an outer band in the southwestern semicircle with infrared cloud top temperatures colder than those currently seen in the inner core. The various satellite intensity estimates have nudged downward, and the initial intensity of 135 kt is at the upper edge of the estimates. Polo is turning more westward with the initial motion now 295/9 kt. A mid-level ridge building westward from northern Mexico should steer the hurricane generally westward for the next 36 h or so. 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 end of the ridge. The track guidance has come into much better agreement on this scenario, although there are significant differences in how fast the storm will move during the recurvature. One on side, the GFS, HCCA, Google DeepMind, and Florida State Super Ensemble are faster, and the official forecast leans towards them. On the other, the UKMET and the regional hurricane models are notably slower with their forward speed. Overall, the new forecast track is near the center of the guidance envelope and is similar to the previous forecast. The new track takes the center away from the southwestern coast of Mexico today and then has it passing over Baja California Sur in 96-120 h. Fluctuations in strength seem likely over the next day or so while Polo undergoes this new eyewall replacement and remains in favorable environmental conditions. The intensity forecast shows little change in strength at 12 h and some slight strengthening at 24 h to try to account for the cycle. After 24 h, a slow weakening is expected through 96 h as Polo encounters somewhat increased shear. The new forecast shows a sharp drop in intensity by 120 h as Polo crosses the Baja California peninsula. The new forecast lies near the upper edge of the intensity guidance. Key Messages: 1. Heavy rainfall associated with Polo will impact coastal portions of southwest Mexico today. This rainfall may produce life-threatening flooding and mudslides, especially in areas of steep terrain. 2. Tropical storm conditions are expected across portions of the coast within the warning area from Tecpan de Galeana to Manzanillo for a few more hours. 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 24/1500Z 16.8N 104.4W 135 KT 155 MPH 12H 25/0000Z 17.0N 105.8W 135 KT 155 MPH 24H 25/1200Z 17.1N 107.8W 140 KT 160 MPH 36H 26/0000Z 17.4N 109.6W 135 KT 155 MPH 48H 26/1200Z 18.2N 111.2W 130 KT 150 MPH 60H 27/0000Z 19.4N 112.5W 125 KT 145 MPH 72H 27/1200Z 21.1N 113.3W 115 KT 130 MPH 96H 28/1200Z 24.4N 113.3W 100 KT 115 MPH 120H 29/1200Z 27.0N 111.1W 75 KT 85 MPH...GULF OF CALIFORNIA $$ Forecaster Beven
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