Tropical Cyclone Discussion
899 WTPZ45 KNHC 080234 TCDEP5 Tropical Storm Simon Discussion Number 3 NWS National Hurricane Center Miami FL EP202026 900 PM CST Wed Oct 07 2026 Simon has continued to become better organized on satellite imagery over the past 6 hours with a large area of deep convection and improved curved banding. A recent WSF-M microwave pass also shows improved curved banding structure. The latest subjective Dvorak classification from TAFB was 3.0/45 kt, and the initial intensity has been raised to 45 kt accordingly, and this could be conservative. Environmental conditions are quite favorable for significant intensification. The SHIPS Rapid Intensity Index indicates greater than a 50 percent chance of 55 kt of strengthening over the next 48 h. Most of the hurricane regional models, as well as HCCA and GDMI show significant intensification over the next couple of days, and the NHC intensity forecast has been increased accordingly. The NHC forecast now indicates a 110 kt intensity at 60 and 72 h, and this is at the high end of the model suite, in good agreement with the HCCA model. The initial motion is west-northwestward, or 290 degrees at 8 kt. Simon is likely to continue this general west-northwestward motion for the next day or so, to the south of a weak mid-level ridge. By Friday, the system should turn northwestward and then northward ahead of a 500 mb trough approaching Baja California. In 3-5 days, the cyclone should move generally northward between a mid-level anticyclone and the trough near Baja California. The official forecast track has been shifted a bit to the left from 12-60 hours, but is nearly on top of the previous track from days 3 to 5, and is quite similar to the latest HFIP corrected consensus approach (HCCA). The forecast takes Simon toward the coast of west-central Mexico as a dangerous major hurricane in a few days. There is a fair amount of spread in the guidance, and that is important to note because Simon is forecast to be moving nearly parallel to the coastline in about 72 hours when it nears west-central Mexico. A track farther west would keep Simon over water longer, but a track farther east would mean a sooner landfall. Key Messages: 1. Simon is expected to strengthen into a hurricane by Thursday night and approach the west-central coast of Mexico as a major hurricane on Saturday. There is a risk of dangerous wind and storm surge impacts along portions of this coast over the weekend and into early next week, and watches could be required overnight into early Thursday. 2. Heavy rainfall associated with Simon will impact portions of southwestern Mexico later this week and into the weekend. This rainfall may produce life-threatening flooding and mudslides, especially in areas of steep terrain. 3. Swells will affect portions of the southwestern and west-central coast of Mexico through the weekend. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office. FORECAST POSITIONS AND MAX WINDS INIT 08/0300Z 15.6N 102.5W 45 KT 50 MPH 12H 08/1200Z 15.8N 103.6W 60 KT 70 MPH 24H 09/0000Z 16.1N 104.6W 70 KT 80 MPH 36H 09/1200Z 16.4N 105.3W 85 KT 100 MPH 48H 10/0000Z 16.9N 105.5W 100 KT 115 MPH 60H 10/1200Z 17.8N 105.6W 110 KT 125 MPH 72H 11/0000Z 18.9N 105.5W 110 KT 125 MPH 96H 12/0000Z 21.6N 105.8W 90 KT 105 MPH 120H 13/0000Z 24.2N 106.8W 70 KT 80 MPH...INLAND