Weather patterns that bring moisture to the southwestern United States have become more rare over the last 35 years, say scientists at the National Center for Atmospheric Research in Boulder.
The study, published in Geophysical Research Letters, found subtle shifts in weather patterns over the southwest, including most of the western half of Colorado. The patterns that tend to bring the most wet weather to the area are low pressure systems, and those have formed less often over the years.
“Drought in the southwest nowadays can occur easier, can last longer, and they are more intense than they were 30 years ago,” said Andreas Prein, a postdoctoral researcher who led the study.
Climate change could provide one explanation for this change, although scientists didn’t look at a direct link in their study, Prein said.