The 2011 tornado season is just getting underway and is already setting damage records, said Eqecat. The firm's estimate is based in part on initial reports of nearly 10,000 buildings destroyed.
The storms killed at least 316 people in six Southern states and left entire neighborhoods in ruins. On Friday, President Obama visited Tuscaloosa, Ala. neighborhoods that were flattened by tornados.
"I've got to say I've never seen devastation like this," the President told reporters.
The storms leveled neighborhoods, rendered major roads impassable and left at least 800,000 customers without power Friday afternoon.
Even with that level of damage, Eqecat's cost estimate for the recent natural disasters in Japan was much higher.
Losses from the quake, tsunami and fires there totaled at least $100 billion, including $20 billion in damage to residences and $40 billion in damage to infrastructure such as roads, rail and port facilities, the firm estimated in March.
In the 1995 earthquake in Kobe, the most expensive earthquake in history, total losses were $100 billion, but insured losses only $3 billion, according to the Insurance Information Institute.