
Photo by U.S. Geological Survey
Flooding of the Mississippi River near the St. Louis Gateway Arch in August, 1993.

Photo by RMCO and NRDC (Figure 2, p.6, from the report “Doubled Trouble: More Midwestern Extreme Storms”)
Average frequency of days with 3 inches or more of precipitation per weather station per year. Dots indicate annual average frequency per station, the blue line the 1961-2011 linear trend line, and the dashed line the average frequency 1961-1990.

Photo by RMCO and NRDC (Figure 9, p.14, from the report “Doubled Trouble: More Midwestern Extreme Storms”)
By-decade changes in the frequency of storms of at least 3 inches in Missouri, compared to a 1961-1990 baseline.

Photo by RMCO and NRDC (Figure 4, p.9, from the report "Doubled Trouble: More Midwestern Extreme Storms")
By-decade changes in the frequency of storms of at least 3 inches in Illinois, compared to a 1961-1990 baseline.