After a quiet start to winter, the season took a turn. While under the influence of La Nina, the second half of the season saw a more active storm track across the Ohio Valley.
That’s not something we expect to change as we head into the spring.
The 90-day outlook for March, April and May is calling for above average temperatures and above average precipitation. The introduction of warmer temperatures will bring an increased severe weather risk and flood risk. In contrast, last spring was quiet in terms of severe weather.
On average, the state of Indiana sees 11 tornadoes during our spring season with most of those occurring in May. Last year, there were only 17 tornadoes across the state.
Ten of those occurred during spring including an EF-1 tornado that struck downtown Mooresville on April 8. The tornado touched down northwest of the intersection of Concord and Main before doing significant roof and tree damage to portions of downtown. The largest damage occurred to a brick building where the roof was blown off. The tornado continued to track to the southeast before damaging a large picnic shelter and crossing State Road 67, before lifting.
In general, the spring season can bring volatile swings in our jet stream pattern. As temperatures start to warm and we’re able to bring more moisture up from the Gulf, there’s a lot more energy available to grow into big, and sometimes severe storms when that air clashes with drier, cooler air from the north.
This year we are still under the influence of La Nina. Typically, springs following La Nina winters tend to be more active with severe weather in the Ohio Valley.
While March is opening like a lamb and we’re seeing temperatures near and above seasonal levels, we will still see cooler than normal spells at times. Storm systems moving through can still bring a wintry potential with them. As temperatures warm through April and heavy rainfall events become more common, flooding concerns will grow. Usually La Nina springs start off cool, but end up with temperatures 2 to 3 degrees above average for the March through May period.
Overall, we are anticipating a warmer, more active severe weather season and you can count on the Forecast First Weather Authority team to give you the information you need to keep you and your family safe.