Tropical Cyclone Discussion
211 WTPZ42 KNHC 231444 TCDEP2 Hurricane Polo Discussion Number 12 NWS National Hurricane Center Miami FL EP172026 900 AM CST Wed Sep 23 2026 Satellite imagery this morning indicates that Polo is continuing to undergo an eyewall replacement cycle, with infrared imagery showing multiple rings of cold tops near and around the center. Overall, the hurricane is not as intense as it was 24 h ago, as the eye has become less distinct and the eyewall cloud tops have warmed. The various satellite intensity estimates have trended downward, and based on this trend the initial intensity is lowered to a possibly generous 130 kt. Outer rainbands in the northeastern semicircle have reached the coast of Mexico. Polo is starting its forecast turn toward the northwest with the initial motion now 325/4 kt. Water vapor imagery suggests a mid-level ridge is building over Texas and Mexico, and the dynamical models forecast this ridge to build westward to the north of Polo for the next 2-3 days. This evolution should result in Polo moving northwestward and then west-northwestward with some increase in forward speed. The forecast becomes more uncertain after 60-72 h. The dynamical models forecast the ridge to the north to weaken around that time as a mid-latitude trough moves into the western United States. There is also the possibility of interaction with Hurricane Odalys to the west. The guidance becomes divergent by 120 h, with the GFS/HCCA/Google DeepMind/Florida State Superensemble showing a northward motion close to Baja California, while the regional hurricane models/UKMET/Canadian show a northwestward motion farther away from Baja. The track forecast goes with the northward motion scenario, but there is a significant amount of uncertainty in this portion of the forecast. The trends of the intensity forecast guidance suggest that Polo could weaken a little during the next day or so, followed by re-intensification during the ensuing 24 h. The first two days of the intensity forecast follow these trends, and there could be fluctuations in intensity due to eyewall replacement cycles superimposed on top of this overall trend. After 48 h, the environment gradually becomes less favorable due to slightly stronger shear and the possibility of some dry air entrainment. The guidance forecast slow weakening during this time, and the new intensity forecast follows suit. The new forecast is 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, and a Tropical Storm Watch is in effect westward to Playa Perula. Interests in these areas should closely monitor updates to the forecast. FORECAST POSITIONS AND MAX WINDS INIT 23/1500Z 15.4N 101.8W 130 KT 150 MPH 12H 24/0000Z 15.9N 102.5W 125 KT 145 MPH 24H 24/1200Z 16.5N 104.0W 125 KT 145 MPH 36H 25/0000Z 16.8N 105.8W 130 KT 150 MPH 48H 25/1200Z 17.0N 107.7W 130 KT 150 MPH 60H 26/0000Z 17.2N 109.6W 125 KT 145 MPH 72H 26/1200Z 18.0N 111.1W 120 KT 140 MPH 96H 27/1200Z 20.7N 112.9W 105 KT 120 MPH 120H 28/1200Z 23.2N 113.1W 90 KT 105 MPH