Jun 17, 2016

Recent Trends in Northern and Southern Hemispheric Cold and Warm Pockets

Richard Grumm and Anne Balogh
National Weather Service and Penn State University Monograph

Finds that from 1980 - 2010:

  • Areas covered by extreme cold air in cold seasons decreased significantly in the northern hemisphere; observed trend was negative but not statistically significant in the southern hemisphere
  • Areas covered by warm air during summer seasons increased significantly in both hemispheres
  • The northern hemisphere is tending toward increasingly warmer and more humid summers: "overall, more warm air, larger ridges, and warmer air"
  • During the warm season, the global area covered by precipitable water values equal to or greater than 60mm is increasing
  • The significant changes in weather are "occurring in the tails of the distribution"