What is a 100 year flood? A 100 year flood is an event that statistically has a 1% chance of occurring in any given year. A 500 year flood has a .2% chance of occurring and a 1000 year flood has a .1% chance of occurring. The map below relates [the] amount of rainfall that fell to the chances of that amount of rain actually occurring.
Climate Progress has been documenting the woefully underreported Tennessee deluge of 2010 aka Nashville’s ‘Katrina’. It was an off-the-charts extreme weather event that human-caused global warming set the table for and almost certainly made more intense, as a leading climate scientist explained to me (interview to be posted next week).
But I didn’t understand just how unprecedented this superstorm was until I saw the above map from the Office of Hydrological Development at NOAA/NWS. I have never seen a map like this before, but then that may be because there simply aren’t many events to rival this one. Look at the red streak, which is the area hit by a greater than 1000-year deluge. And look at how much of western Tennessee was slammed with a greater than 500 year downpour. This is the “high water” of Hell and High Water.
The NWS has more maps that put the deluge in perspective, including how it compared to Hurricane Katrina’s rainfall:
Here are some amazing factoids:
- Fifteen (15) observation sites had rainfall measurements exceeding the maximum observed rainfall associated with Hurricane Katrina landfall.
- The two day rainfall of 13.57 inches at Nashville International Airport shattered the monthly rainfall record for May which was 11.04 inches.
- The rainiest month in Nashville is 13.92 inches in January 1950.
- Nashville International Airport experienced its 1st and 3rd rainiest days on back to back days.
- The heaviest rainfall occurred in a swath across Davidson, Williamson, Dickson, Hickman, Benton, Perry, and Humphreys Counties. An average of 14 to 15 inches of rain fell equivalent to 420 billion gallons of water in just two days.
And here is what Katrina did:
So yes, this superstorm deserve to be called Nashville’s Katrina. It is all the more stunning for having generated so much rain without actually being associated with a hurricane, similar to the Georgia superstorm from September (see Weather Channel expert Stu Ostro’s discussion of Georgia’s record-smashing global-warming-type deluge).
I suppose people can stick their head in the sand water if they want, but CP readers understand that this is the shape of things to come for many of the world’s great cities if we stay anywhere near our current greenhouse gas emissions path. More on the way.
Related Posts:
- Must re-read statement from UK’s Royal Society and Met Office on the connection between global warming and extreme weathern
- Global warming means local (super) storming
- Northeast hit by record global-warming-type deluge
- Australian Scientists: Contrary to media reports, “our paper does not discount climate change as playing a role in this most recent drought, the ‘Big Dry’. In fact, there are indications that climate change has worsened this recent drought.”
- Preparing For Frankenstorms: “The most powerful low pressure system in 140 years of record keeping” slams the Southwest.
- In other UK news: “Rain like this happens once every 1,000 years”
- Global boiling: Freak storms on every continent
- Why the “never seen before” Fargo flooding is just what you’d expect from global warming, as Obama warns
- Massive moisture-driven extreme precipitation during warmest winter in the satellite record — and the deniers say it disproves (!) climate science
- MSNBC’s Ratigan: “These ‘snowpocalypses’ that have been going through DC and other extreme weather events are precisely what climate scientists have been predicting, fearing and anticipating because of global warming.”
- The non-blizzard of 2009 and why the anti-science disinformers try to shout down any talk of a link between climate change and extreme weather