Isaias About to Hit Florida, Simon Threatens Mexico, Rachel Could Impact the Southwest: AI Models Discussion 10-9-2026

We will take a tour around the Northern Hemisphere tropics today, including a look at several systems that will be impacting land.

Atlantic

The Atlantic’s first hurricane of the year, Isaias, has formed over the Northern Gulf. It is currently a Category 3 hurricane, and moving towards the Florida Panhandle (Figure 1). It is forecast to weaken slightly due to strong upper-level shear prior to landfall, but could still be a very impactful hurricane. It is worth noting that Google DeepMind has performed very well with both the track and intensity of this storm, consistently showing it intensifying to a major hurricane and making landfall in the Panhandle.

Behind Isaias, there are no clear signals for development. A few members show something could develop in the subtropics, and there is also some signal for another system to develop in the NW Caribbean or Gulf. The upper level winds seem fairly divergent over the NW Caribbean in around 8 days (Figure 2), so we’ll see if there is a system there to take advantage before El Niño shear shuts things down.

East Pacific

There are a couple of systems of note in the East Pacific. The first is Tropical Storm Rachel, which is winding down over cooler waters but is forecast to move northeast towards Northern Baja California (Figure 3).

Although it may not make a direct landfall in California, the moisture from the system, along with the forcing from an upper trough, may produce significant rainfall across portions of Southern California, Nevada, and Arizona (Figure 4).

The system behind Rachel is Hurricane Simon, which is currently tracking parallel to the coast of Mexico and intensifying. It is forecast to continue to intensify, with most of the Google DeepMind ensemble showing it becoming a major hurricane (Figure 5).

Simon will also be turning NE ahead of an upper trough (Figure 6), and is likely to make landfall along the western coast of Mexico, somewhere in the vicinity of Puerto Vallarta. This definitely has the potential to be very impactful, especially if it intensifies significantly.

There is some signal for yet another storm to form south of Mexico in the medium range (Figure 3), as the extremely active 2026 East Pacific season rolls on for a bit longer.

West Pacific

In the West Pacific, Typhoon Koguma is recurving to the Southeast of Japan, and Nolo (which has moved across almost the entire Pacific!) is following behind it (Figure 7).

Behind these 2 systems, models are starting to show another robust signal for development to the East of the Mariana Islands, with the potential for a strong typhoon to develop. Upper-level winds look like they will be favorable for development and intensification (Figure 8).

Folks in the Mariana Islands and points further west should keep a close eye on this potential system, and see how the development evolves next week.

We’ll be back with another update soon! Stay safe everyone.