Hurricane Isaac caused wind damage that could reach $1-2 billion, disaster modeler RMS said in an update on the 2012 Atlantic hurricane season. This season is proving the second most active since records began in 1851, with only 2005 and 2011 having more named storms as of September 13, the San Francisco-based RMS said. The first hurricane to hit the United States this year, Isaac struck New Orleans last month, almost exactly seven years after Hurricane Katrina devastated the city, but it proved to be a much less damaging storm. RMS’ estimate excludes all losses caused by flooding and all losses from the National Flood Insurance Program.