Fall tornado season could be active in Middle Tennessee this year Alex Libby — WKRN News 2

We are more than halfway through October and that means Tennessee is entering its secondary tornado season.

NASHVILLE, Tenn. (WKRN) — We are more than halfway through October and that means Tennessee is entering its secondary tornado season.

Tennessee’s primary tornado season occurs during the spring and peaks in April. The secondary tornado season is in the fall and peaks in November.

Historically, November has been Middle Tennessee’s fifth most active month for tornadoes.

The secondary tornado season is caused by the polar jet stream migrating back down over our area at the same time there is still enough heat and moisture in the Gulf of Mexico.

Tornadoes need wind shear and energy to form. The jet stream brings the wind shear and the warm Gulf of Mexico brings the energy. During the fall, and especially the spring, both of these ingredients are present.

During the summer, there is plenty of energy. However, there is typically not enough wind shear. During the winter, there is plenty of wind shear, but typically not enough energy.

Matt Elliott, a warning coordination meteorologist at the Storm Prediction Center, said that this fall’s tornado season could be more active than in previous years.

“La Niña across the southeast and Tennessee valley does lead to above active seasons typically. There really isn’t a signal with the strength of La Niña,” Elliott told News 2. “Really, at any La Niña signal can lead to an enhanced activity.”

La Niña is the cold phase of the El Niño Southern Oscillation. Elliott added that almost all of Tennessee’s most active fall tornado seasons occurred during past La Niñas. The latest forecast from the Climate Prediction Center is for La Niña to continue into November and last through the winter.

Now is the best time to prepare for the upcoming fall severe weather season. That means having a tornado-safe place and making sure you have multiple ways to receive warnings.

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