We thank Steve Gray, Adam Phillips, and Justin Sheffield for assistance and for data, and we are especially grateful to Dave Meko for sharing his Matlab code to calculate PDSI and the Palmer Z index. We appreciate the helpful reviews we received from Mike Evans, Zack Holden, and Andrew Ray. This project was supported in part by an NSF doctoral fellowship to T. Ault, a NCAR-ASP fellowship to T. Ault, NOAA CCDD (NA07OAR4310054) and NSF P2C2 (0903093) support for J. Cole, and NOAA Climate Program Office support for CLIMAS (J. Overpeck). Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
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