wind shear

The reason this area is key is because it hosts the best wind shear and instability.

That’s because it tends to reduce wind shear in the tropics, enabling hurricanes to grow in strength, and keeps Atlantic Ocean water warm, which helps fuel storms.

“This is because of the anticipated onset of La Niña, which suppresses wind shear, and the anomalous lingering warmth that’s expected to remain in the tropical Atlantic and in the Caribbean,” Grow Cei said.

"Yes, more water vapor in the air can foster stronger convection, but a tornado is a very local feature and requires a very specific set of meteorological conditions, such as the right wind shear."

The spot could have formed as a result of a gigantic superstorm, similar to those occasionally observed on Jupiter's twin planet Saturn; from the merging of multiple smaller vortices produced by wind shear from the intense wind currents that flow parallel to each other, but alternating in direction with latitude; or from an instability in the winds that could produce an elongated atmospheric cell, similar in shape to the Spot.