Remember Invest 91L, that tropical wave that had a high chance of becoming a tropical disturbance? Well, this same wave’s tropical development chances wind down, and it now has no opportunity to develop in the short or long term.
What happened?
In the note published on Wednesday, we mentioned the dry air in place over the Caribbean. There is another mass of dry air, moving ahead of what was Invest 91L, which has significantly limited the chances of this disturbance developing. When we look behind it, there is a layer of Saharan dust moving right behind it, which will continue to move west, a bit faster above it, and continue to choke this system, preventing it from developing altogether.
A deep plume of Saharan dust is following in the wake of what was Invest 91L, which, with dry air ahead of it, has lost its battle and now has a ZERO chance of tropical formation. Good news as we approach the peak of this hurricane season. pic.twitter.com/ukyBexXaBv
— Florida Public Radio Emergency Network (FPREN) (@FloridaStorms) September 7, 2025
Good reminder
This serves as a great example of why we shouldn’t completely rely on one model, and even less so on one or a few runs. Additionally, we follow a list of names. Although it serves as a good reminder to indicate which one comes next on the list, it is not good practice to "name" systems before they are officially designated by the National Hurricane Center. As it has just happened, a disturbance with a high chance of developing may occur, but this chance could quickly diminish if the atmospheric conditions change.