Increases in Amounts of Very Heavy Precipitation (1958 to 2007)
The map shows percent increases in the amount falling in very heavy precipitation events (defined as the heaviest 1 percent of all daily events) from 1958 to 2007 for each region. There are clear trends toward more very heavy precipitation for the nation as a whole, and particularly in the Northeast and Midwest. Image Source: Updated from Groisman et al.1
- 1.  Groisman, P.Ya., R. W. Knight, T. R. Karl, D. R. Easterling, B. Sun, and J. H. Lawrimore. "Contemporary Changes of the Hydrological Cycle over the Contiguous United States: Trends Derived from In Situ Observations." Journal of Hydrometeorology 5, no. 1 (2004): 64-85.