The Storm Prediction Center has put almost all of Louisiana south of U.S. Highway 190 at a slight risk for severe weather today. As if Tropical Storm Cindy tracking just south of the coast wasn't enough there is also the threat of tornadoes.

It is not uncommon for land falling tropical systems or tropical systems that are in such a close proximity to the coast to spawn tornadoes. A tornado watch has been posted for much of southeast Louisiana until 10 AM.  Currently, that watch does include Iberia, St. Martin, and St. Mary Parishes in Acadiana.

The reason for the severe weather and tornado threat is because of the massive supercell thunderstorms that often accompany tropical systems. These supercell storms already contain rotation within their structure. There are also other ingredients that make the atmosphere primed for tornadoes to quickly spin up.

There is a lot of wind shear in a tropical system. That means winds blowing from different directions through different altitudes. There is also instability in the atmosphere as rising warm air meets cooler air. The warm air wants to go up, the colder air wants to sink. This could bring a rotating column of air down to the ground.