Tropical Cyclone Discussion
996 WTPZ42 KNHC 232049 TCDEP2 Hurricane Polo Discussion Number 13 NWS National Hurricane Center Miami FL EP172026 300 PM CST Wed Sep 23 2026 Satellite imagery this afternoon suggests that Polo seems to be at or near the end of its eyewall replacement cycle, as the eyewall cloud tops have gotten colder during the past several hours, and the eye is gradually becoming more distinct. The various satellite intensity estimates are lower than they were six hours ago, but they are no longer falling. The initial intensity is lowered to 125 kt, and for the moment that could still be a little generous. The hurricane's outer rainbands continue to affect the coast of Mexico. The hurricane is now moving faster toward the northwest at 310/6 kt. Water vapor imagery suggests a mid-level ridge is building over Texas and northern Mexico, and the dynamical models forecast this ridge to build westward to the north of Polo starting on Thursday as an upper-level trough near Baja California weakens and lifts out. This evolution should result in Polo moving northwestward for 12 h or so, followed by a west-northwestward motion with some increase in forward speed. There have been changes in the forecast guidance since the last advisory for the forecast period after 60 h. The cluster of models that was forecasting a northward motion has shifted a touch to the west, while the cluster that was forecasting a more northwestward motion has shifted more northward. So, while there is still spread and uncertainty, the guidance is a little more clustered than before. The biggest changes are the ECMWF and the UKMET, which are now part of the northward moving cluster. The new forecast track for this period follows the northward cluster to a position west of Baja California by 120 h. Overall, the new track is similar to the previous track through 72 h and a little west of the previous track after that. The intensity guidance continues to suggest a little decrease in intensity during the next 12-24 h followed by slight strengthening. However, since Polo is completing its eyewall replacement, it is possible that intensification could occur at any time. So, the new intensity forecast now shows re-intensification during the next 24 h. After 48 h, the environment gradually becomes less favorable due to slightly stronger shear and the possibility of some dry air entrainment. The guidance forecasts slow weakening during this time, and the new intensity forecast follows suit. The new forecast is again near the upper edge of the guidance for the first 60 h and then lies closer to the middle of the guidance envelope. While the center of Polo is forecast to remain offshore, outer rainbands should spread across southwestern Mexico during the next day or so, producing areas of heavy rain and tropical-storm-force winds. Key Messages: 1. Heavy rainfall associated with Polo will impact coastal portions of southwest Mexico through Thursday. This rainfall may produce life-threatening flooding and mudslides, especially in areas of steep terrain. 2. A Tropical Storm Warning is in effect for portions of southwestern Mexico from Tecpan de Galeana to Punta San Telmo, and a Tropical Storm Watch is in effect west of that to Playa Perula. Interests in these areas should closely monitor updates to the forecast. FORECAST POSITIONS AND MAX WINDS INIT 23/2100Z 15.7N 102.4W 125 KT 145 MPH 12H 24/0600Z 16.2N 103.4W 130 KT 150 MPH 24H 24/1800Z 16.7N 105.0W 135 KT 155 MPH 36H 25/0600Z 16.9N 106.9W 135 KT 155 MPH 48H 25/1800Z 17.2N 108.9W 130 KT 150 MPH 60H 26/0600Z 17.7N 110.6W 125 KT 145 MPH 72H 26/1800Z 18.9N 112.0W 120 KT 140 MPH 96H 27/1800Z 22.2N 113.4W 105 KT 120 MPH 120H 28/1800Z 24.3N 113.4W 90 KT 105 MPH