National Geographic: This years heavy, widespread snowfall across the interior U.S. has people watching flood forecasts for the Mississippi River Basin closely, as the ground thaws and thunderstorm season cranks up. This is understandable, as three memorable 100 year floods struck the Mississippi River Basin in 17 years--in 1993, 2008, and 2011--with more local flooding in between. While this years Mississippi River flood forecast appears moderate, planting season is a good time to reflect on recent history and...