1. National Drought Mitigation Center, University of Nebraska-Lincoln, Lincoln 68583, USA
2. Cooperative Institute for Meteorological Satellite Studies, Space Science and Engineering Center, University of Wisconsin-Madison, Madison 53706, USA
3. CNRM UMR 3589, Météo-France/CNRS, Toulouse 31057, France
4. School of Natural Resources, University of Nebraska-Lincoln, Lincoln 68583, USA
5. Conservation and Survey Division, School of Natural Resources, University of Nebraska-Lincoln, Lincoln 68583, USA