Today marks the 40th anniversary of the devastating flash flood that hit the Big Thompson canyon in Colorado, killing 144 people and causing tremendous damage to the area on that Saturday evening in 1976.  The flood was not well predicted due to the high elevation, which reduced radar visibility of the storm that funneled all the rain into the narrow canyon.  You can read more about it at Weather Underground here.

While you might think that flash floods are more frequent in mountainous areas, you can also get devastating rainfall events in the East on relatively flat areas.  Earlier this weekend a local flood brought over 8 inches of rain in just a few hours to Ellicott City, just west of Baltimore MD.  You can see some videos and read about it here and here and at Weather Underground here.

Because high-intensity storms are increasing everywhere in the US, emergency planners are starting realize that old methods for planning for flooding  are not working well anymore.  Scientific American has an interesting article discussing some of the changes that will be needed in https://www.scientificamerican.com/article/u-s-needs-smarter-disaster-planning/.  It’s also discussed at Climate Progress at https://thinkprogress.org/climate/2016/07/28/3802705/flooding-impacts/.

Source: USGS
Source: USGS