Every so often, the waters of the eastern Pacific off the coast of South America get extraordinarily warm, producing trillions of joules of energy that wreak havoc with our weather. The phenomenon, of course, has come to be known as El Nino. Regions like the southwestern U.S., Mexico and South America are slammed with sometimes catastrophic rain, while other areas suffer through record drought. The phenomenon seemingly appears every two to seven years, but meteorologists still are handcuffed when it comes to accurately predicting its cycle. Host Joe Hanson takes a crack at explaining El Nino and why it remains so difficult to predict in this edition of “It’s Okay to be Smart” from PBS Digital Studios.