Eqecat has estimated claims of $US1-$2 billion ($94 million to $1.9 billion) from the tornadoes that hit the US Midwest and southern states in the first week of this month.

The forecaster says over 150 tornadoes touched down in two distinct systems between February 28 and March 3, causing damage and 49 deaths in Tennessee, Kentucky, Indiana, Illinois, and Alabama.

It says the 272 tornadoes to hit so far this year are well above the average for the previous seven years of 123 events.