AIR estimates insured U.S. storm, tornado damage in May to range between $4 billion and $7 billion

Catastrophe modeling firm AIR Worldwide estimates the outbreak of severe thunderstorms that struck the United States between May 20 and 27 will result in insured losses between $4 billion and $7 billion.
AIR’s insured loss estimates reflect insured physical damage to property -residential, commercial, industrial and auto (both to structures and contents), as well as additional living expenses for residential claims, business interruption losses and the effects of demand surge.
They do not reflect non-modeled losses, including loss adjustment expenses.
“The month of May, normally the most active month for tornadoes, began quietly,” said Dr. Tim Doggett, principal scientist at AIR Worldwide. “For three weeks, only a handful of isolated tornadoes were reported.
“But on May 20, severe thunderstorms in eastern Texas and parts of Arkansas and Oklahoma brought high winds, hail and five reported tornadoes. Over the next seven days, more than 150 confirmed tornadoes raged across the heart of the country.”
None of the individual meteorological elements that gave rise to the outbreak of severe thunderstorms is unusual, Doggett said.
“Large, strong, jet stream disturbances happen occasionally,” he said. “Persistent low pressure frontal systems are common, especially in spring. And the storms that developed occurred where they are expected to occur at this time of year.
“What is unusual is for all of the factors that contribute to the development of severe thunderstorms to have aligned themselves so optimally in the same place at an opportune time. To get optimal intense instability, shear and lift all in the same place for a long period of time is a relatively rare circumstance.”
Doggett added the 2011 tornado season is on track to rival the very active 2008 season.
“It is also becoming quickly apparent that 2011 will surpass 2008 in terms of insured losses from severe thunderstorm activity,” Doggett said. “Indeed, the two major outbreaks of this year – the first in late April, the second in late May – are the costliest on record.”