The U.S. Drought Monitor: Evolution and recent achievements

While many things have changed over the past 15 years with the U.S. Drought Monitor (USDM) (Svoboda et al., 2002), the fundamental process of the USDM remains true today, which integrates multiple inputs, a percentile approach and expert input from experts in the field. It is obvious why there isn't, and shouldn't be, just one definition (Wilhite et al. 1985 and Lloyd-Hughes, 2013) of drought being applied today around the world, yet many think that there can be, or should be, just one drought index or indicator that addresses all types of drought. The fact is, the timing, region, intensity and duration are different each time and thus require a uniquely flexible way of detecting and depicting drought through a diligent Drought Early Warning System (DEWS). We don't have the luxury of seeing a drought approaching via satellite or radar, and forecasts are still very limited in their skill horizon, so it behooves us all to establish and utilize an early warning system that can diligently watch and wait for drought to emerge. Although drought indices and indicators have been around for nearly a century, we have only recently begun to use new technology and integrated approaches as a means of helping us address a hazard as complex as drought. When combined, these new tools and approaches have helped us advance our drought monitoring and early warning system capacities around the world. In turn, many of these tools and derivative products have been integrated into the USDM process leading to a more accurate and precise product over the years. This paper will outline the process, key milestones and recent progress, applications and achievements of the USDM.