The U.S. is in the grip of a searing heat wave, with temperature warnings and advisories in effect for a large stretch of the central part of the country. States in the south and southwest have been experiencing extreme weather for many months, resulting in a severe drought across a belt of 14 states from Florida to Arizona. Crops and livestock are suffering, as farmers and ranchers struggle to keep them alive. But with no rain in sight and a shaky economy, some are questioning whether this could be a 21st century Dust Bowl. Pete Bonds,  a cattle rancher from Saginow, Texas, is in Omaha on his way to Iowa in search of new grass to feed his cattle. He says in 55 years of living on a cattle farm, this is the worst drought he's ever seen.  Dr. Donald Wilhite, founding director of The National Drought Mitigation Center and now director of the School of Natural Resources at the University of Nebraska-Lincoln, concurs with Bonds. He thinks this drought, caused by La Nina, is likely the worst since the 1950s.