 In addition to becoming the second-largest Atlantic hurricane, Sandy broke records for the lowest pressures ever observed in many cities across the Northeastern United States.The origins of Hurricane Sandy trace back to a tropical wave that moved off the western coast of Africa and into the eastern Atlantic Ocean on October 11.As the wave tracked westward over subsequent days, it interacted with an upper-level trough over the Eastern Atlantic, resulting in the development of widespread shower and thunderstorm activity; however, strong wind shear prevented further development at the time.