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The parade of tropical systems continues as we approach the peak of hurricane season

Sept. 9 satellite image of the tropics.
Sept. 9 satellite image of the tropics. (CIRA/RAMMB)

There’s a striking string of tropical storms and tropical-storm wannabes over the eastern tropical Atlantic and the African continent. It seems likely that we’ll get at least a Sally and Teddy out of this group, which leaves only Vicky and Wilfred before we run out of regular names and have to resort to the Greek alphabet.

Tropical Storm Paulette is proceeding toward the central Atlantic. It has jogged a bit to the west, but is still forecast to turn to the north. It may intensify a bit before it runs into increasingly hostile upper-level winds. In any case, it is not expected to be a threat to land.

Rene temporarily weakened to a tropical depression as it moved over the Capo Verde Islands just west of Africa. It looks like the atmosphere ahead of Rene is a bit more favorable for strengthening than for Paulette, so it’s still forecast to reach hurricane strength. A break in the blocking high-pressure system that has been spanning the Atlantic is expected to allow the system to follow Paulette to the north before it affects any more land areas, so Rene shouldn’t be a problem.

The next system off the coast of Africa, Disturbance #2, is another story. It’s not clear that there will be an alleyway this system can take to the north. The computer forecast models are all over the place, which means there’s a fork in the road ahead, and it’s too close to call whether it will turn north or continue west.

Since it’s coming off Africa at a lower latitude, it may get caught in the general east-west trade-wind flow and come closer to the Caribbean islands. It’s too early to know. Computer forecast models indicate that the atmosphere ahead of the disturbance will be conducive for it to fairly quickly become a tropical depression or tropical storm.

The computer forecast models that turn potential Sally north move it into the same general part of the ocean that will be occupied by Paulette and Rene. It’s not out of the question that the storms would interact in some squirrelly fashion, but they should stay away from land even if that happens.

Disturbance #2 will move off the African coast tonight or tomorrow.

Behind that one, Disturbance #3 is clearly identifiable. It’s too early to prognosticate its future, though the atmosphere ahead appears reasonably conducive for it to organize after it moves offshore over the weekend.

On our side of the Atlantic, the National Hurricane Center continues to make note of a disturbance that’s heading for the Carolina coast – Disturbance #1. It’s not likely to become very strong even if it develops an organized circulation and becomes a tropical depression. In any case, it should enhance the already rainy weather pattern along the East Coast tonight and tomorrow.

Sept. 9 satellite image of Disturbance #1.
Sept. 9 satellite image of Disturbance #1. (CIRA/RAMMB)

With so many storms running around in the Atlantic at the same time, be ready for the computer forecast models to change their projections day to day. When well-developed systems come within about 900 miles of each other, they deflect each other throwing each one off track, depending on how strong they are. These so-called binary interactions are impossible to forecast because they are super-dependent on the exact location and strength of each system.

Even with all of that, no significant threats to land are expected through the weekend, at least.


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