Colorado's Biblical Record Rainfall: The Scary Statistics Of the Flood


Rainfall in Boulder, Colo., has hit an all-time high. There has been more rainfall in the past three days than over a typical six month period. According to Climate Central, over three days, 24-hour rainfall totals of between 8 and 10 inches across Boulder area were enough to qualify it as a 1 in 1,000 year event. This is a 0.1% chance of occurring in any given year.

This rare event has lead people, including the National Weather Service, to label the storm as “Biblical.” It may seem strange that a scientific organization dedicated to climate research would use such a label, but there are reasons for this. The Bible actually contains many references to storms and severe weather conditions symbolizing events out of our control. Also, Biblical doctrine was written during a time when mysticism was much more valued than science. Given what was believed to be an improbable situation, people are inclined to associate it to supernatural intervention.   

Meteorologists and climate change activists have been closely following the development of Boulder’s record rainfall. Here are some statistics, courtesy of Boulder weather observer Matt Kelsch

- Five of the past eight days set daily rainfall records.

- The 9.08 inches that fell on Sept. 12 was an all-time single-day record, nearly doubling the previous record of 4.80 inches set on July 31, 1919.

- As of 7 a.m. on Monday, Boulder’s monthly rainfall during September stood at 17.17 inches, all but 0.02 inches of which fell during the past week. The previous all-time monthly record was 9.59 inches in May of 1995.

These figures are leaving people terrified with the outcome and further potential harm this flood might cause. Even storm veterans and those prepared to ward off rising waters didn’t stand a chance considering the storm’s unprecedented impact. On Monday, over 1,000 have been reported missing – many unreachable by phone.

Spokeswoman for the Colorado Division of Homeland Security and Emergency Management Micki Trost said to USA Today, "We don't expect to find 1,254 fatalities.”

A storm like this begs to question: a result of climate change, a sheer misfortune, or a supernatural act? Robert Henson, a meteorologist at the University Corporation for Atmospheric Research in Boulder is concerned. “If your climate is not stationary then that adds another wrinkle to the statistics.”

This speaks to the unpredictability of future climate change, and how the modeling used today might be obsolete tomorrow. According to the draft National Climate Assessment report, increases in the frequency and intensity of extreme precipitation events are projected for most U.S. areas, which will not bode well for those who live in low-lying areas like Denver.