Extraordinarily large crown fires have burned during recent decades in some western US forests as a consequence of forest and climate changes. Wind events have played important roles in driving major runs during many of these wildfires, including the most rapid burning rates yet recorded in some forests, at more than 40,000 acres per day, over multiple days. Tom Swetnam, Director, Laboratory of Tree Ring Research, College of Science at the University of Arizona, gives his compelling perspective on changing atmospheric circulation patterns and consequent effects on both drought, winds and extreme fire behaviors. Recorded on 3/4/2014. (#28237)