The reported 129 tornadoes that struck the central and southeast U.S. between March 2 and March 3 would place the outbreak as the highest number storms during the month of March since records began tracking activity in 1950, according to catastrophe modeling firm Risk Management Solutions (RMS).
That sets up the U.S. insurance industry for major losses if the activity continues through the current season.
“While this year’s activity is already high, the peak months of tornado activity across the U.S. have yet to come,” Neena Saith, director of catastrophe response at RMS. “Last year, the months of April through July saw the highest number of tornadoes for 2011, with 758 tornadoes spawning in April.”
The RMS statement add that while there is uncertainty surrounding U.S. tornado activity for the rest of 2012, contributing factors such as warm, moist air from Gulf of Mexico is a “potential indicator of tornado activity levels”. “[Temperatures] in the Gulf of Mexico are currently running between 22 to 24°C, which is around 1°C above average,” RMS said. “The positive anomaly present in the Gulf of Mexico at the moment increases the potential for an active tornado season.”
Other factors, including El-Nino Southern Oscillation (ENSO), may also contribute since El Niño and La Nina forces shift the location and strength of storms in “Tornado Alley.” The RMS statement adds that the “International Research for Climate and Society is reporting that weak La Nina conditions exist at the moment but the La Nina is dissipating and neutral conditions are forecast to take hold over the next few months.”
The March storms tore across Alabama, Georgia, Illinois, Indiana, Kentucky, Mississippi, North Carolina, Ohio, South Carolina, Tennessee, and Virginia last week bringing hail, high winds, and tornadoes to the region.
The strongest tornadoes confirmed in the outbreak two EF3 storms, with two in Kentucky and one in Georgia, RMS said.
