Severe storm frequency may increase this Spring


TERRE HAUTE, Ind. (WTHI) – Severe weather could pop up early once again this year and active storms could visit us more frequently this Spring.

The Storm Prediction Center has already put the valley in the Slight severe weather risk category and we’re just getting out of the first week of February. It goes to show that severe weather can happen at any time of year provided you have the right storm “ingredients”.

These are: lift, moisture, instability, and shear.

The position of the jet stream helps in the lift category and can also determine where other parts of the severe weather recipe come together.

During an El Nino pattern the jet is farther south and generally the storms are too. La Nina, which we’re currently exiting, keeps the jet more northerly along with it’s storms. Since we’re in a transition period, the jet will be more at mid-latitude…and so will the storms.

The storms could be more potent with better access to moisture from the Gulf of Mexico. That moisture helps to fuel instability (buoyant hot air beneath cold air)because when that water cools and releases heat to the air.

Having the storm circulations closer to us also add changes in wind speed and direction with height, known as shear. This can lead to strong, rotating thunderstorms when paired with the other thunderstorm “ingredients”.

Due to a developing, progressive mid-latitude jet pattern, it’s very possible for the Wabash Valley to get more springtime severe weather compared to other years.

Storm Team 10 will go more in depth with severe weather awareness during Indiana’s Severe Weather Preparedness Week beginning March 19th.