Tropical Cyclone Discussion
361 WTPZ42 KNHC 260256 TCDEP2 Hurricane Polo Discussion Number 22 NWS National Hurricane Center Miami FL EP172026 800 PM MST Fri Sep 25 2026 Another NOAA research aircraft investigated Polo extensively this afternoon. The aircraft found that the minimum pressure of Polo has decreased slightly since the last advisory, to 911 mb. The highest flight-level winds measured by the aircraft were 154 kt, which corresponds to a 10-m wind near 140 kt. Higher instantaneous winds representing gusts were measured by several dropsondes, while another experimental instrument measured winds at near 80 m/s (155 kt) at a height of 25 m. Since the plane flew a non-standard pattern on its research mission and the central pressure has actually slightly decreased, the intensity has been only very slightly lowered to 150 kt for this advisory. Fluctuations in intensity due to an eyewall replacement cycle are possible tonight and tomorrow, but the exact timing of such events can not be reliably forecast. Most guidance indicates that Polo will begin to gradually weaken over the next couple of days as it moves into a region of lower ocean heat content and encounters some moderate vertical wind shear. Drier environmental mid-level air could also contribute to weakening by the end of the weekend. However, it must be stressed that Polo will likely remain a dangerous major hurricane as it begins to approach the Baja California peninsula on Monday. The NHC intensity forecast remains on the upper end of the intensity guidance and no changes of note were made. Polo has continued westward for the past several hours. There is no change to the track forecast reasoning with this advisory. The hurricane is still expected to turn gradually northwestward tomorrow, then northward by the end of the weekend while it moves around the western side of a ridge centered over northern Mexico. Early next week an upper-level trough approaching from the northwest will cause the hurricane to turn northeastward toward Baja California Sur and west-central Mexico. Some of NHC's most reliable track guidance, including the GDM and HCCA continue to be outliers in showing a faster track, bringing Polo to the coast of Baja California Sur sooner than most other guidance. Out of respect for this guidance, the NHC track forecast has been adjusted slightly faster and farther north again, but is generally very similar to the previous advisory. 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 west coast of the Baja California peninsula on Monday as a hurricane, and a Hurricane Watch is now in effect for that region. Tropical Storm conditions could reach portions of the coast as soon as Sunday, making further preparations difficult. A storm surge will be possible, especially in areas onshore winds. 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. 3. Dangerous surf and rip currents are likely along portions of the northwest coast of Mexico for the next several days. FORECAST POSITIONS AND MAX WINDS INIT 26/0300Z 17.4N 110.1W 150 KT 175 MPH 12H 26/1200Z 17.8N 111.4W 145 KT 165 MPH 24H 27/0000Z 19.0N 112.8W 135 KT 155 MPH 36H 27/1200Z 20.6N 113.6W 125 KT 145 MPH 48H 28/0000Z 22.6N 113.8W 115 KT 130 MPH 60H 28/1200Z 24.6N 113.4W 100 KT 115 MPH 72H 29/0000Z 26.3N 112.1W 80 KT 90 MPH 96H 30/0000Z 29.8N 109.1W 40 KT 45 MPH...INLAND 120H 01/0000Z 31.6N 105.7W 25 KT 30 MPH...POST-TROP/INLAND