AIR Worldwide has estimated that insured losses from the winter storm which impacted East Coast of the US between February 23 and 28 will be between $150m and $350m. The total insured losses from two prior storms, which occurred between February 4 and February 7 and February 9 and February 11, respectively, are estimated by AIR at between $400m and $1bn.

As a result of storm, the potential for roof damage is increased. As with the two earlier storms, damage caused by snow accumulation is expected to be a source of insured losses from this new event, the firm said.

According to AIR Worldwide, the design loads for structures vary across the US. As little as zero pounds per square foot is allowed in Florida, southern Louisiana, Texas, and parts of Southwest, while as much as GBP100 per square foot is required in Michigan’s Upper Peninsula and northernmost Maine.

In addition, the design snow load for Washington, DC, is about 30 pounds per square foot. With this tolerance, light metal and long-span roofs are vulnerable to snow loads, as are flat or low-slope roofs. Ten to 20 inches of snow can produce loads of roughly 15 to 30 pounds per square foot on flat roofs.

Peter Dailey, director of atmospheric science at AIR Worldwide, said: “The third winter storm to slam the Northeast coast last month reached its height on Friday, February 26, impacting nine states in the mid-Atlantic and New England through Saturday.

“The storm, a powerful low pressure system, originated off the mid-Atlantic coast, intensifying as it came ashore. It moved slowly into New York Friday morning and gradually dissipated over New England over the weekend before moving out to sea.”