“Biblical Rainfall Amounts Reported” in Parts of Colorado

By Tom Yulsman | September 12, 2013 12:33 pm

Flood waters pour into an underpass on the University of Colorado campus in Boulder last night. (Photo: Courtesy Brandon Randash via Instagram.)

Ordinarily, the forecast discussion pages of National Weather Service forecasts are clipped, cut and dry. But not the one issued an hour ago for the Denver-Boulder area:


And the forecast is for “lots more rain today and tonight.”

A photo by the Colorado State Patrol shows the rampaging Big Thompson River along Highway 34 just west of Loveland. (Photo: CSP Larimer Twitpic)

As the photo above suggests, more rain could be devastating.

As I’m writing this, Fourmile Creek, which drains an area highly prone to erosion and flooding thanks to the 2010 Fourmile Canyon Fire, is flooding into northern neighborhoods of Boulder. And that is just one of many such stories being repeated this morning up and down Colorado’s Front Range.

This is a very bad situation. And it’s getting worse.

Dry Creek in Niwot, CO, 1:30 a.m., 9/12/13, a block from my house. It is ordinarily two feet wide. Here, it is at least 25 yards wide, and five feet higher than normal. (Photo: © Tom Yulsman)

Some context: We went from breaking record high temperatures last week (including tying the record — twice — for the highest temperature ever recorded in September in the Denver area), to what appears to be unprecedented torrential rainfall that has caused devastating flash flooding and killed at least two people in this area, and another person further south.

Some numbers to consider: Over the past 18 hours or so, Boulder has received 9 inches of rain. By comparison, average total precipitation for Boulder for the entire month of September is just 1.68 inches. And the record tally for the entire month was 4.67 inches, according to a weather forecaster on Channel 7 here.

The proximate cause is tropical, monsoonal moisture streaming up from the south and a stalled front that is pinning it all right over us.

Check back later for more about the weather patterns implicated in this extreme weather event, and other updates.


  • GivesItThought

    “Biblical Rainfall”? Does that mean it’s a myth? (Snicker!)

  • andrew oh-willeke

    FYI. From a personal safety perspective, taking cover in an underpath under a bridge as the bicyclist does in the top picture is an extremely dangerous thing to do (even though it seems natural) that you shouldn’t try at home unless you have a death wish. A large percentage of people who die in flash floods each year are doing precisely what the person in the picture is doing.

    Hiding under a bridge when a flash flood is in progress is akin to walking around holding a tall metal pole in the middle of a perfectly flat field in the middle of an intense thunderstorm – it is asking for trouble.

    • Maurizio Morabito

      I was just having the same thought. This must be the first major flooding event full of rather playful images.



ImaGeo is a visual blog focusing on the intersection of imagery, imagination and Earth. It focuses on spectacular visuals related to the science of our planet, with an emphasis (although not an exclusive one) on the unfolding Anthropocene Epoch.

About Tom Yulsman

Tom Yulsman is Director of the Center for Environmental Journalism and a Professor of Journalism at the University of Colorado, Boulder. He also continues to work as a science and environmental journalist with more than 30 years of experience producing content for major publications. His work has appeared in the New York Times, Washington Post, Audubon, Climate Central, Columbia Journalism Review, Discover, Nieman Reports, and many other publications. He has held a variety of editorial positions over the years, including a stint as editor-in-chief of Earth magazine. Yulsman has written one book: Origins: the Quest for Our Cosmic Roots, published by the Institute of Physics in 2003.


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