MEMPHIS, Tenn. — It’s a sound all too familiar to Mid-Southerners – tornado sirens blaring across the region over the weekend as multiple twisters touched down.

This scenario is unfortunately not uncommon and the reason why has everything to do with geography.

“The Mid-South is in this unique position in the United States thanks to its proximity to the gulf,” said NWS Memphis Science and Operations Officer Mike Johnson. “So we’re allowed this abundance of moisture that streams into the area ahead of these strong storm systems.”

Along with moisture, the Mid-South gets clashing air masses.

“You can get the arctic air that descends from Canada, you can have the dry air that comes out of the desert southwest and even that dry air can make it into the Mid-South,” said Dorian Burnette, the associate professor of meteorology at the University of Memphis.

When the gulf moisture clashes with these air masses from out west, storms start to form.

“Usually when it makes it this far east, no good comes of that,” Burnette said.

Warmer temperatures in the gulf and the fact that we’re in a La Nina year is leading to an increasing number of tornadoes in the region.

“The scientific literature has shown that when they’re anomalously warm it can be easier for that moisture to advect northward and increase the count of those severe thunderstorms,” Burnette said.