© NOAAThis image from the Suomi NPP satellite's VIIRS sensor from the evening of September 11, 2013, shows the storm system that has devastated towns in the foothills of the Rockies in central Colorado.
Such floods have a 1 percent and 0.1 percent chance of occurring, respectively, during any given year. While those odds make them rare events, they are the result of natural larger-scale weather and climate patterns, with perhaps an assist from climate change.
Still, some Internet users have voiced alternative views, suggesting that the destructive rainstorms were more directly human-induced, the result of Colorado's cloud-seeding program.
Cloud seeding, in which tiny silver iodide particles are sprayed into clouds to provide a core for ice crystals to form around, falls within the Colorado Weather Modification Program that is overseen by the Colorado Water Conservation Board and is used primarily by ski resorts to increase the snowpack during the winter.
The program - which has been reported to increase the snowpack by 10 to 15 percent each year - remains controversial among those concerned about the unknown repercussions of manipulating weather in this way.
