1. National Drought Mitigation Center, School of Natural Resources, University of Nebraska-Lincoln, 816 Hardin Hall, 3310 Holdrege Street, P.O. Box 830988, Lincoln, Nebraska 68583-0988, 68588, U.S.A.
2. National Agroclimate Information Service, Agriculture and Agri-Food Canada, 960 Carling Avenue, Ottawa, ON K1A 0C6, Canada
3. Center for Advanced Land Management Information Technologies, University of Nebraska, Lincoln, Nebraska 68588, U.S.A.
4. United States Geological Survey, Earth Resources Observation and Science Center, 47914 252nd Street, Sioux Falls, South Dakota, U.S.A.