Evaluating climate model simulations of drought for the Northwestern U.S.

Researchers from Oregon State and the University of Idaho developed a framework to help evaluate the fidelity of global climate models (GCMs) to simulate regional drought. They focused on the northwestern United States and found that model fidelity was generally higher for drought metrics evaluated with evapotranspiration versus precipitation and for seasonal/annual timescales versus multi-year timescales. They also found that models systematically underestimated the severity of regional drought in the region of focus. Their research aims to do two things: help those who use regional climate projections where drought plays an important role and highlight shortcomings of model simulations of hydroclimate variability.