Tropical Cyclone Discussion
249 WTPZ41 KNHC 151458 TCDEP1 Hurricane Trudy Discussion Number 9 NWS National Hurricane Center Miami FL EP212026 900 AM CST Thu Oct 15 2026 Trudy appears to be undergoing a period of rapid intensification. After the previous advisory, there were several microwave images that showed the hurricane has developed an eyewall, with a cyan ring noted on the 37 GHz channel of the 1037 UTC GMI and more recent 1250 UTC WSF-M pass. This signature is often a harbinger or indicates that rapid intensification is underway. On geostationary satellite Trudy has been maintaining a healthy central dense overcast with cold cloud tops between -75 to -80 C with new bursts of convection fully wrapping around the circulation as it becomes more symmetric. The subjective Dvorak estimate at 12 UTC was T4.5/77 kt, but given the improving structure seen on microwave imagery, the initial intensity is being set at 80 kt this advisory, which is on the high end of the intensity estimates. This indicates that Trudy has intensified 30 kt in the past 24 h, qualifying as rapid intensification. An Air Force Reserve Hurricane Hunter aircraft is en route to sample the hurricane and should provide critial in-situ data to help refine the forecast this afternoon. Trudy is now estimated to be moving slowly north-northwestward, or 335 degrees at 5 kt. Over the next 24-36 h Trudy is expected to maintain this heading but at a slow pace as its steering is maintained by two ridges, one to its east and another to its north. These features are split by a mid- to upper-level trough that is draped across the Yucatan Peninsula, weakening the overall steering flow. How these synoptic features interact over the next several days is leading to a lot of track uncertainty over the next few days, and there are some track solutions (GFS, ECMWF) that show Trudy making landfall. The latest NHC track forecast has been shifted eastward compared to the prior one, following the trends in the guidance. This track is blending the latest HFIP Corrected Consensus Approach (HCCA), Google DeepMind ensemble mean (GDMI) and also places a little weight on the latest ECMWF track forecast. With that said, given the spread of the deterministic and ensemble track guidance this cycle, this forecast is lower confidence than usual. Now that Trudy has developed an inner-core, intensification is likely to be rapid in the short-term. Environmental conditions are quite favorable (shear under 10 kt, sea-surface temperatures 28-29 C, and abundant moisture) and SHIPS-RI indices are elevated for a 30-40 kt increase in intensity over the next 24 h. Thus, the first part of this intensity forecast was raised from the previous advisory, showing Trudy becoming a major hurricane in 12-24 h, and peaking as a 125 kt Category 4 hurricane in 36 h. This part of the intensity forecast is on the upper end of the guidance. Thereafter, both the GFS and ECMWF based SHIPS guidance shows southwesterly vertical wind shear increasing markedly, and this will also be the period where Trudy nears the coast of Mexico, where terrain-induced effects will likely start to affect the circulation. These combined effects are now forecast to lead to weakening beginning in 48 h and continuing through the rest of the forecast. One big caveat with this intensity forecast is just how close Trudy gets to Mexico. A track closer to the coast may result in much more weakening than shown here, while a track further offshore may preserve Trudy's intensity, similar to what we saw with Simon earlier this week. The second part of the NHC intensity forecast falls back closer to the guidance mean. Given the proximity of Trudy's track to Mexico, this is also a lower confidence intensity forecast after the next 48 h. KEY MESSAGES: 1. Trudy is forecast to be a major hurricane as it approaches the coast of southwestern and west-central Mexico this weekend. There is an increasing risk of wind, rain, and storm surge impacts. A Tropical Storm Watch has now been issued for a portion of the southwestern Mexican coast, and additional watches will likely be required further up the coast later today. 2. Heavy rainfall associated with Trudy will impact the southwest Mexican coast between Guerrero and Jalisco through the weekend. This rainfall may produce life-threatening flooding and mudslides by the weekend across Colima and Jalisco, especially in areas along steep terrain. 3. Large swells will begin to affect portions of the coast of southwestern Mexico Friday and continue through the weekend. These swells could cause life-threatening surf and rip current conditions. FORECAST POSITIONS AND MAX WINDS INIT 15/1500Z 13.1N 101.6W 80 KT 90 MPH 12H 16/0000Z 13.6N 101.9W 95 KT 110 MPH 24H 16/1200Z 14.6N 102.2W 115 KT 130 MPH 36H 17/0000Z 15.5N 102.5W 125 KT 145 MPH 48H 17/1200Z 16.7N 103.4W 120 KT 140 MPH 60H 18/0000Z 18.0N 104.3W 105 KT 120 MPH 72H 18/1200Z 19.4N 105.4W 90 KT 105 MPH 96H 19/1200Z 20.2N 107.4W 55 KT 65 MPH 120H 20/1200Z 20.3N 108.4W 50 KT 60 MPH