USA Gulf of Mexico -- 28 Aug 2012 -- On August 28, 2012, tropical storm Isaac achieved hurricane force and was predicted to make landfall on the Gulf Coast of the United States sometime overnight. A category 1 storm, Hurricane Isaac approached the Louisiana and Mississippi coasts on the seventh anniversary of Hurricane Katrina. Hurricane watches and warnings were posted from Intracoastal City, Louisiana, to the Mississippi-Alabama border -- Picture by Lightroom Photos/NASA