It’s the peak of the Atlantic hurricane season, and the tropics are bonkers

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A satellite image of the state of play Thursday across the tropics.
Enlarge / A satellite image of the state of play Thursday across the tropics.

The historical peak of the Atlantic hurricane season—the point at which, climatologically speaking, the most activity takes place—is today. And this being 2020, the Atlantic tropics are not wanting in vim and vigor.

The latest outlook from the National Hurricane Center shows two active named systems in the Atlantic: tropical storms Paulette and Rene. Although both of these storms should turn north well short of the continental United States, there is some concern about Paulette reaching Bermuda as a Category 1 hurricane by early next week.

Looking beyond these two storms reveals no fewer than four “areas of interest” to watch on the hurricane map.

Five-day tropical outlook issued at 2pm ET Thursday.
Five-day tropical outlook issued at 2pm ET Thursday.
National Hurricane Center

Two of these are close to the United States: one feature lies in the northern Gulf of Mexico (with a 20 percent chance of becoming a tropical depression or storm over the next five days), and the second should cross Florida into the Gulf this weekend (40 percent chance). Generally, forecast models are not overly bullish on these storms developing into strong tropical storms or hurricanes, but they could bring some heavy rain to much of the Gulf Coast over the next week.

The other two features are near Africa, and these are what we expect to see at this time of year, when low-pressure systems move off the African continent into the warm Atlantic waters and begin to develop. Of these two tropical waves, we’re more concerned about the southernmost one, which has a 90 percent chance of developing over the next five days. We’ll call it the “African wave.”

European ensemble forecast for Wednesday evening, September 16. This shows the potential outcomes for the African wave.
European ensemble forecast for Wednesday evening, September 16. This shows the potential outcomes for the African wave.
Weather Bell/Ars Technica

The models are ultimately split on whether this potent wave curves north over the open Atlantic—like Paulette and Rene—and follows a more westerly track toward the Caribbean Sea and ultimately the United States. If the African wave were to become stronger more quickly, it would probably turn fairly soon. If it remains weaker it has a better, chance to travel more due west.

What does seem clear is that we are in for a bonkers period in the Atlantic Ocean, with multiple storms and areas of interest. This afternoon’s deterministic run of the European model shows the interaction of multiple systems subjecting themselves to the Fujiwhara effect next week. This highest-resolution version of the model, for what it’s worth, shows a stronger African wave that turns north fairly early.

European model forecast for low-pressure anomalies for next week.
European model forecast for low-pressure anomalies for next week.
Weather Bell

It is quite a zany dance, but if these storms remain out to sea then, hey, go crazy, 2020.

https://arstechnica.com/?p=1705160