Science Source

More frequent intense and long-lived storms dominate the springtime trend in central US rainfall

Finds that large regions of the central United States experienced statistically significant upward trends in April–June mesoscale convective systems (MCSs) rainfall of 0.4–0.8 mm per day (approximately 20%–40%) per decade from 1979 to 2014
Finds upward trends in MCS frequency of occurrence, lifetime, and precipitation amount, which they attribute to an enhanced west-toeast pressure gradient (enhanced Great Plains low-level jet) and enhanced specific humidity throughout the eastern Great Plains
Shows plots of trends in surface and 850 hPa specific humidity of 0.4 and 0.2 g/kg/decade, respectively, from 1979–2014 for the April–May–June period across the Midwest—representing increases of approximately 5% and 3% per decade, respectively