Understanding the 2011 Upper Missouri River Basin floods in the context of a changing climate

A detailed analysis of the record 2011 flood event shows that streamflow generated over the region's easternmost sub-basin is acutely sensitive to antecedent moisture. Yet, the 2011 record streamflow cannot be explained by a single factor or as the result of long-term trends, with the basin responding to several independent factors; significantly high (p < 0.05) antecedent moisture and significant cold-season precipitation. Perhaps most importantly was the record-setting May precipitation, which limited the ability of ensemble streamflow simulations initialized on 1-March from reliably predicting the record June streamflows. The recent volatility of UMRB streamflow may be a harbinger of future decades based on our analysis of climate projections that indicate increased hydroclimate variability by the latter half of the 21st century.