Nov 11, 2016

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

Zhe Feng, L. Ruby Leung, Samson Hagos, Robert A. Houze, Casey D. Burleyson, Karthik Balaguru
Nature Communications
  • 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