Tropical Cyclone Discussion
329 WTPZ42 KNHC 270857 TCDEP2 Hurricane Polo Discussion Number 27 NWS National Hurricane Center Miami FL EP172026 200 AM MST Sun Sep 27 2026 The satellite presentation of Polo has remained fairly steady since the time the NOAA aircraft finished its mission about 7 hours ago. There are still hints of an eye in geostationary and microwave satellite images. The latest TAFB Dvorak currently intensity was 6.5/127 kt with 5.5/102 kt for the final-T number. Objective intensity estimates from UW-CIMSS have been running in the 105-110 kt range. The initial intensity is held at 105 kt for this advisory. Polo has turned toward the north-northwest, with the current motion estimated at 330/9 kt. A turn toward the north is expected later today, and then northeastward on Monday as the cyclone continues to move around the ridge and becomes increasingly affected by a mid- to upper-level trough moving in from the northwest. The largest source of uncertainty in the forecast continues to be the forward speed of Polo as it makes its expected northeastward turn between the aforementioned synoptic features. The model spread remains higher than unusual between 48 and 72 h, more so for the along-track forward speed of the storm after landfall. The NHC forecast follows the path of the GDMI and HCCA, but is a bit slower than those models. This forecast is essentially on top of the previous NHC forecast. Polo will continue to travel through an environment of fairly weak vertical wind shear and sea-surface temperatures near 29C for the next 24 h, but will be moving into a somewhat drier airmass. By hour 36, which is about 6 hours before landfall, southwesterly vertical wind shear will increase. Due to the favorable conditions until almost before the Baja California landfall, the NHC forecast is near the higher end of the guidance suite through hour 36, showing only gradual weakening. Thereafter, increasing wind shear and land interaction will cause rapid weakening. Although waters are warm in the Gulf of California, Polo is not expected to restrengthen there due to strong southwesterly vertical wind shear. The intensity forecast for the 2nd landfall (in mainland Mexico) is tricky. There is some possibility that Polo could still be at hurricane strength for the 2nd landfall, as suggested by the latest HAFS-A forecast. Polo should dissipate inland over northern Mexico by hour 72. Polo is expected to become a remnant low and then dissipate before it reaches the southern U.S., but distant moisture associated with it and Odalys will be transported into the southwestern United States late 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 Warning is in effect for that region. Tropical storm conditions could reach portions of the coast as soon as tonight or early Monday, making further preparations difficult. These conditions will likely spread across Baja California through Monday. A storm surge is likely, especially in areas of onshore winds. 2. Heavy rainfall associated with Polo may begin to impact Baja California Sur tonight into Tuesday. 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 and Baja California for the next few days. FORECAST POSITIONS AND MAX WINDS INIT 27/0900Z 20.3N 113.6W 105 KT 120 MPH 12H 27/1800Z 21.6N 114.0W 100 KT 115 MPH 24H 28/0600Z 23.4N 114.0W 95 KT 110 MPH 36H 28/1800Z 25.1N 113.1W 90 KT 105 MPH 48H 29/0600Z 26.8N 111.6W 70 KT 80 MPH 60H 29/1800Z 28.9N 109.3W 40 KT 45 MPH 72H 30/0600Z 31.3N 106.8W 25 KT 30 MPH...POST-TROP/INLAND 96H 01/0600Z...DISSIPATED