William M. Gray, 86, emeritus professor of atmospheric science at Colorado State University (CSU) and a pioneer of hurricane forecasting, has died. Gray, who headed the Tropical Meteorology Project, issued his first data-driven seasonal forecast at CSU in 1984. Rather than determining a tropical storm's path or potential landfall, Gray is considered instrumental in using aggregated data to determine atmospheric conditions, water currents and temperatures to predict the number and intensity of storms. He received his bachelor's degree in geography from George Washington University in 1952 before joining the U.S. Air Force, where he was a weather forecaster, and he earned a master's degree in meteorology and a doctorate in geophysical sciences from the University of Chicago. Gray joined CSU in 1961 and retired in 2005, but he remained active in weather research. Gray, whose wife died in 2001, is survived by three children. The CSU's 2016 hurricane forecast, issued earlier this month by Gray's final graduate student Philip J. Klotzbach, now lead author, calls for an "average" major hurricane season (see Daily GPI, April 15).