Tropical Cyclone Discussion
076 WTPZ42 KNHC 272050 TCDEP2 Hurricane Polo Discussion Number 29 NWS National Hurricane Center Miami FL EP172026 200 PM MST Sun Sep 27 2026 A NOAA P-3 Hurricane Hunter aircraft was able to complete two fixes into Polo earlier this afternoon, indicating the hurricane was more or less steady state. In the final fix, the aircraft reported a 22 n mi closed eyewall, though in the wind data there was some evidence of a double wind maximum at 700 mb even though the secondary wind max was not seen in the Tail Doppler Radar wind data. The peak flight-level winds were 117 kt, which typically reduces to 105 kt using a standard 0.9 reduction. However, the aircraft did not fully sample the eastern quadrant where higher winds may exist. In addition, subjective and objective satellite intensity estimates remain at or above 110 kt, so Polo's initial intensity will be held at 110 kt this advisory. Polo is continuing its turn, now moving northward at 355 degrees at 10 kt. The synoptic setup and track reasoning has not chanced much this cycle, with Polo expected to move between deep-layer ridging centered over Mexico and a shortwave trough that will soon move into California. This trough is forecast to sweep southward, helping to capture the smaller Polo, leading it to accelerating to the northeast. The NHC track forecast this cycle is largely an update of the previous one this morning, though there remains more along-track spread, related to Polo's speed of motion, than across-track spread. This latest track lies closest to the Google DeepMind ensemble mean (GDMI). With the latest update to the track, a Hurricane Warning has now been issued for portions of mainland Mexico along the Gulf of California. Vertical wind shear in the SHIPS guidance is in the 5-10 kt range for the next 12-24 h while the hurricane traverses 28-29 C sea-surface temperatures, so Polo's short-term intensity will likely be controlled by inner-core fluctuations. Given the double wind maxima that appeared in the earlier aircraft data, it is not out of the question another eyewall replacement cycle (ERC) could occur before Polo makes landfall along the west Baja California Sur coastline. The latest NHC intensity forecast shows very little change in strength before Polo reaches the coast, and the latest forecast now anticipates Polo making landfall at near major hurricane intensity. In fact, both the 12z HAFS-A/B raw model output show Polo making landfall as a major hurricane even if their interpolated aids are a bit lower in intensity. Significant weakening should occur as it moves over the rugged terrain of the Baja California Peninsula, but Polo will likely still be a hurricane when it makes its second landfall in mainland Mexico. Rapid weakening is forecast thereafter and Polo will likely dissipate before the middle of this week over the Mexican Plateau. Polo is expected to dissipate before it reaches the southern U.S., but distant moisture associated with it and Odalys will be transported into the southwestern United States during the next few days, 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 and into mainland Mexico on early Tuesday. A storm surge is likely, especially in areas of onshore winds. 2. Heavy rainfall associated with Polo may begin to impact Baja California Sur later tonight into Tuesday and portions of Sonora late Monday into Tuesday. This rainfall may produce life-threatening flooding and mudslides, especially in areas of steep terrain. Moisture from Polo will support heavy rainfall and flooding potential across the Southwest U.S. into the Southern High Plains late Monday into Tuesday. 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 27/2100Z 21.9N 114.1W 110 KT 125 MPH 12H 28/0600Z 23.2N 114.0W 110 KT 125 MPH 24H 28/1800Z 25.0N 113.0W 105 KT 120 MPH 36H 29/0600Z 27.0N 111.3W 75 KT 85 MPH...OVER WATER 48H 29/1800Z 29.9N 108.7W 35 KT 40 MPH...INLAND 60H 30/0600Z...DISSIPATED