AP: Calling deadly Tennessee superstorm an “unprecedented rain event” did “not capture the magnitude”

Plus Dr. Jeff Masters on the link to warming (and USGS myopia)

Tennessee Gov. Phil Bredesen called it an “unprecedented rain event,” but that statement did not capture the magnitude. More than 13 inches of rain fell in Nashville over two days, nearly doubling the previous record of 6.68 inches that fell after Hurricane Frederic in 1979.

“That is an astonishing amount of rain in a 24- or 36-hour period,” Bredesen said Sunday.

Don’t worry, anti-science disinformers who try to shout down any talk of a link between climate change and extreme weather, the AP/WashPost story never mentions global warming.  Indeed, I couldn’t a single story on the superstorm that did.

Not that there were that many stories on the deluge at all given 1) the other mega-stories of the weekend and 2) the fact this didn’t occur on one of the coasts where Big Media lives.

But the fact that this superstorm blew away rainfall records set from the remnants of a hurricane three decades ago bring to mind Weather Channel expert Stu Ostro’s discussion of Georgia’s record-smashing global-warming-type deluge.  Of course, Ostro pointed out there was no way to know if global warming had “caused” the record floods, but

Nevertheless, there’s a straightforward connection in the way the changing climate “set the table” for what happened this September in Atlanta and elsewhere. It behooves us to understand not only theoretical expected increases in heavy precipitation (via relatively slow/linear changes in temperatures, evaporation, and atmospheric moisture) but also how changing circulation patterns are already squeezing out that moisture in extreme doses and affecting weather in other ways.

Meteorologist Dr. Jeff Masters discusses the superstorm on his must-read WunderBlog:

Nashville, Tennessee remains virtually paralyzed this morning thanks to that city’s heaviest recorded 1-day and 2-day rainfall in its history. A remarkable 7.25″ of rain fell on the city Sunday, breaking the record for most rain in a single day (previously 6.60″, set September 13, 1979.) Nashville’s third greatest day of rainfall on record occurred Saturday, when 6.32″ fell. Nashville also eclipsed its greatest 6-hour and 12-hour rainfall events on record, with 5.57″ and 7.20″, respectively, falling on Sunday. And, remarkably, only 2 days into the month, May 2010 is already the wettest May on record for Nashville.

Rainfall records were smashed all across Tennessee and Kentucky, with amounts as high as 17.73″ recorded at Camden, TN, and 17.02″ at Brownsville, TN….   Tennessee had its rainiest day in its 63-year weather history on Sunday, 7.93″. Bowling Green, Kentucky had its heaviest 2-day precipitation event on record, 9.67″. Records in Bowling Green go back to 1870….

The record rains were accompanied by a surge of very warm air that set record high temperature marks at 21 major airports across the Eastern U.S. on Saturday; 19 more records were set on Sunday. This is not surprising, since more moisture can evaporate into warmer air, making record-setting rainfall events more likely when record high temperatures are present.

Masters discusses the link to global warming and the tragic shortsightedness of government officials:

According to the USGS web site, seventeen Tennessee streamflow gages with records going back up to 85 years will stop collecting data on July 1 because of budget cuts. With up to thirteen people in Tennessee dying from flooding this weekend, now hardly seems to be the time to be skimping on monitoring river flow levels by taking 17 of Tennessee’s 94 streamflow gages out of service. These gages are critical for proper issuance of flood warnings to people in harm’s way.

Furthermore, Tennessee and most of the northern 2/3 of the U.S. can expect a much higher incidence of record flooding in coming decades. This will be driven by two factors: increased urban development causing faster run-off, and an increase in very heavy precipitation events due to global warming. Both factors have already contributed to significant increases in flooding events in recent decades over much of the U.S. According the landmark 2009 U.S. Climate Impact Report from the U.S. Global Change Research Program, “the amount of rain falling in the heaviest downpours has increased approximately 20 percent on average in the past century, and this trend is very likely to continue, with the largest increases in the wettest places.”

… Tennessee is not the only state with streamgages at risk of closing down; fully 276 gages in 37 states have been shut down or will be shut down later this year [see Figure below — more details at USGS.]

So much for the notion that we are going to prepare or adapt for climate change.  Heck, we’re not even gonna pay to completely monitor the change.

For the sake of completeness, for those who haven’t read my recent posts on this subject — such as “Northeast hit by record global-warming-type deluge” and “Global warming means local (super) storming” — here’s some more background on the link between global warming and extreme precipitation.  Regular readers can skip the rest of this post.  You can find more here and there’s some terrific technical meteorological analysis here.

In 2004, the Journal of Hydrometeorology published an analysis by NOAA’s National Climatic Data Center that found “Over the contiguous United States, precipitation, temperature, streamflow, and heavy and very heavy precipitation have increased during the twentieth century.”

They found (here) that over the course of the 20th century, the “Cold season (October through April),” saw a 16% increase in “heavy” precipitation events (roughly greater than 2 inches [when it comes as rain] in one day), and a 25% increase in “very heavy” precipitation events (roughly greater than 4 inches in one day)- and a 36% rise in “extreme” precipitation events (those in the 99.9% percentile “” 1 in 1000 events). This rise in extreme precipitation is precisely what is predicted by global warming models in the scientific literature.

In fact, the last few decades have seen rising extreme precipitation over the United States in the historical record, according to NCDC’s Climate Extremes Index (CEI):

An increasing trend in the area experiencing much above-normal proportion of heavy daily precipitation is observed from about 1950 to the present.

Here is a plot of the percentage of this country (times two) with much greater than normal proportion of precipitation derived from extreme 1-day precipitation events (where extreme equals the highest tenth percentile of deluges, from NOAA):

CEI-4 2009

It is the compounding of “typical” extreme weather events on top of human-caused climate change that creates the devastating, record-smashing “global-warming-type” events.  To re-excerpt the Must re-read statement from UK’s Royal Society and Met Office on the connection between global warming and extreme weather:

We expect some of the most significant impacts of climate change to occur when natural variability is exacerbated by long-term global warming, so that even small changes in global temperatures can produce damaging local and regional effects. Year on year the evidence is growing that damaging climate and weather events “” potentially intensified by global warming “” are already happening and beginning to affect society and ecosystems. This includes:

* In the UK, heavier daily rainfall leading to local flooding such as in the summer of 2007;
* Increased risk of summer heat waves such as the summers of 2003 across the UK and Europe;
* Around the world, increasing incidence of extreme weather events with unprecedented levels of damage to society and infrastructure. This year’s unusually destructive typhoon season in South East Asia, while not easy to attribute directly to climate change, illustrates the vulnerabilities to such events;
* Sea level rises leading to dangerous exposure of populations in, for example, Bangladesh, the Maldives and other island states;
* Persistent droughts, leading to pressures on water and food resources, and the increasing incidence of forest fires in regions where future projections indicate long term reductions in rainfall, such as South West Australia and the Mediterranean.

These emerging signals are consistent with what we expect from our projections, giving us confidence in the science and models that underpin them. In the absence of action to mitigate climate change, we can expect much larger changes in the coming decades than have been seen so far.

In short, get used to it.

And remember, this is all from about a 1°F warming in the last few decades.  We are on track to see nearly 10 times that over much of the United States on our current emissions path (see “Our hellish future: Definitive NOAA-led report on U.S. climate impacts warns of scorching 9 to 11°F warming over most of inland U.S. by 2090 with Kansas above 90°F some 120 days a year “” and that isn’t the worst case, it’s business as usual!“)

In short, we ain’t seen nothing yet.

As always, the events I focus on here in this context are the record-smashing ones, the super-duper storms:

Global warming means local super-storming.

25 Responses to AP: Calling deadly Tennessee superstorm an “unprecedented rain event” did “not capture the magnitude”

  1. PurpleOzone says:

    A disaster-authority (khaki-uniformed person, I didn’t catch her exact title) in Tennessee said on the TV this storm was a one in 500 year event. She’d never seen anything like it.

  2. Rocky Raneldo says:

    Droughts would become permanent. I wonder where we read about floods in this area 400 or 500 years ago?

  3. Aaron Lewis says:

    Flood gauges are really to gather climate data for the area to allow engineered structures to be designed and built. With global warming, the concept of “climate” (and engineering) goes out the door. With global warming we can’t estimate future weather based on past weather (or stream gauges).

    What we can be sure of is that as the Arctic goes from being cold and dry to being an ocean that absorbs heat; and pumps latent heat into the atmosphere, our weather will change in unpredictable ways. Under those conditions, no amount of stream gauge data is going help us predict future stream levels.

    Instead of engineering structures for the local climate, with global warming we either build “disposable” structures that are washed away in the next big flood or we design and build very expensive structures that will withstand almost anything.

    This is a large and real cost of global warming that has not been explored.

  4. David B. Benson says:

    Aaron Lewis — Probably go back to fords for streams and ferry boats for rivers.

  5. Lore says:

    What about all the minor stories of extreme weather that don’t make the national news? For instance Sault Ste. Marie, Michigan, just North of me, had the warmest April in 122 years of records. There were 13 days above 60F, normally there are none and two days of previously unrecorded high temperatures in the upper 70s.

    It’s only when we get the wrath of god in biblical proportions which includes loss of life that the media takes notice, yet they are still afraid to make the obvious connections and report it to the public. It amounts to nothing more then journalistic malfeasance for the sake of your advertiser revenue.

  6. john atcheson says:

    Statistical outliers of this magnitude — so-called Black Swans — are always discounted. But let’s get real: When you double the previous record, it literally cries out for an explanation. And that explanation is global warming.

  7. Dyuane says:

    It is sad that peopled died. But we shouldn’t build homes in the low lying land. They washed away from previous storms….

  8. BB says:

    @John atcheson …

    JR is right to posture about extreme weather events when dealing with something of this locallized nature. It may have doubled the Nashville record, but you’re talking about a single location there. If an area as large as Tennessee had a previous record of only 7″ in 24-hours…that itself would be the outlier, as most similar states are well over 10″.

    West Virginia is wide-accepted to have had a single location get 19″ of rain in 2 hours back in 1889 (Rockport, WV, I believe). For what explanation does that cry out..?

    Everyone does this.

    However, there definitely needs to be a maintaining of all the stream gauges and such to monitor incoming water. Often large river crests can be predicted many hours in advance…but not if there’s no data…and the Doppler network has holes in it when it comes to this.

  9. Mike Roddy says:

    Extreme flooding is part of desert ecology. In Yucca Valley, where I used to live, it rained 4″ per year, but there were only a few times of the year when it rained. Flooding was always a problem when this happened, including closed roads and boulders cascading down hills from the water.

    Desertification is a predicted outcome of warming in the Southwest, but we may see it in the Southeast, too. Trees can’t easily survive in 110 degree summers.

  10. Lewis Cleverdon says:

    The line I find most potent in discussing climate, particularly with farming neighbours, is to remark the 35 year timelag on emissions’ warming impact – i.e. that the commonplace 100-yr weather events we’re seeing in Britain reflect GHG emissions from the mid-’70s, with CO2 at 330 ppmv.

    If you ask where we’ll be as farmers once the impacts of present emissions take effect, off 390 ppmv of CO2 (which is roughly a doubling of the excess carbon), they tend to blanch and either swear or go silent.

    To put this in context of local experience, for the last two years running a ‘monsoon’ started in mid-June and finished in mid-September, destroying many grain crops and almost all the upland hay – meaning heavy costs buying in winter fodder. The effect of those monsoons on the native mountain livestock is very noticeable – they’ve lacked the summer boost to their health and vitality that formerly got them through the winters. Death rates have been raised.

    Last year was also the first in living memory where the oaks produced no acorns at all.



  11. Mike says:

    This April was the warmest on record in Illinois. Last May Southern Illinois was hit with a bizarre, unprecedented, “inland hurricane.” We are 3 hours north of Nashville.×5630623

  12. Leif says:

    Global energy imbalance is a much more descriptive term than global warming.

    When looking at the ~ 0.5 C warming of the earth over the last 50+ years it is easy to dismiss it as error or no big deal. However the energy that has been absorbed to raise the whole of the earth including the top 2,000 feet of ocean is enormous. Back of the napkin calculations give numbers like 190,000 nuclear power plants shorting all there energy into the oceans every day. With about 10 new plants coming on line every day. That energy in turn has evaporated additional water vapor, (~3.5% extra), equivalent to ~1.5 times the volume of Lake Superior to cruse our atmosphere. (projected to be about 3 times the volume by 2050) This water vapor must return to earth as rain, floods, or even snow in the winter. Recall as well that as that additional water vapor condenses and falls it is immediately replaced with additional evaporation from those 190,000+ nuke plants as we are talking equilibrium here and a new base state that is constantly growing. The extra latent heat given off by this additional condensation in turn adds energy to storms. tornadoes hurricanes, jet streams, pressure systems, Arctic outflows, the whole shebang.

    Prepare to swallow your gum on a regular bases folks.

  13. Brian says:

    We had 2 “rain events” of epic proportions in CT this Spring as well. In the span of ten days we had two separate periods of more than 5 inches of rain…

    That shit ain’t natural.

  14. Leif says:

    Quite the contrary Brian, #13: It is the “new natural” as the earth is doing what it has always done and that is to attempt to reach equilibrium with energy balance. You can say that it is not normal but it is quite natural. So learn to enjoy the show as earth attempts to balance the energy imbalance of our hubristic actions on natural systems…

  15. Fire Mountain says:

    It is amazing that the part of the U.S. that leans the furthest right, still debating Darwin let alone global warming, is also one of the world’s premier weather machines. I’m referring to the broad swathe from the Southeast through Great Plains, where the warm wet air off the Gulf of Mexico meets cool air from the Arctic via the jet stream. a.k.a., the storm track. This one that hit Tennessee and Kentucky looked on the maps like a firehose tracking straight from the Gulf. We’re all getting hit and going to get hit, but these places are going to get hit the hardest. Perhaps the Bible Belt should turn to that phrase of scripture that reminds us whatever we sow we will also reap.

  16. BillD says:

    I’m looking forward to temperature and weather summaries for April, both for regions in the US and global values. Seeing highs in the mid 80s in central Michigan in early April was shocking to me.

    I hope that the coming hurricane season does not offer a “one-two punch” to the Gulf Coast. They are suffering enough.

    I planted a vegetable garden a month earlier than usual in northern Iniana. Seems that I could have started two months earlier.

  17. Barry says:

    Great point Fire Mountain (#15).

    I guess the South really can claim to be the land that God has not forgotten….with Biblical weather like towns being blown away, forests ripped from their roots, major cities flooded and broken, burning oceans and tempests spawning monster tornado clusters.

    Seems a dangerous beast to be feeding a billion pounds of extra “fuel” every hour like we are now.

    Wonder how much superstorming it will take before the South finally turns alternative energy sources?

  18. J4zonian says:

    “Indeed, I couldn’t [find] a single story on the superstorm that did.”

  19. prokaryote says:

    Some updates on the record breaking rains in the Tennessee area.
    People on twitter call this already Nashlantis.

    Flooding death toll in Southeast U.S. floods rises to 24

    Updated: 12:25 PM GMT on May 05, 2010

  20. substanti8 says:

    This great video by Nashville resident Michael Deppisch went viral.  He combined his original camerawork with perfect music.

  21. substanti8 says:

    Followup to my last comment …

    I posted a (quite reasonable) comment about climate change below Michael Deppisch’s video, but he erased it within minutes and blocked me from all contact with him.  Perhaps he’s a climate change denier.  He lives in Dixie, after all.

  22. Bruce says:

    Some of you people are nuts. It is just not reasonable to take a couple of hundred (at most) years of data and draw the kind of conclusions you are. Is climate change real? Probably. Do we need alternate fuels and serious conservation methods? Absolutely! To say that superstorms are caused by the South’s failure to use alternative fuels is a clear sign of an unbalanced mind.

  23. Leif says:

    Bruce, #22: It is not just the South’s failure but humanities failure and your inability to see the handwriting on the wall is the essence of our destruction.

    Take 18 minutes and watch this video and do yourself and loved ones a great favor.

  24. Bruce says:

    Leif. I watched all 18 minutes and while I am sure that this is a convincing argument to you sorry but I didn’t find it life altering. Yes we are over fishing the ocean in some places, fertilizers are a big problem. But rather than rational measures and common sense solutions he states that in 20 years all life in the ocean will be dead, except minnows. The biggest problem for environmentalists is the radical whackos who see every event, whether natural or artificial, as a sign that proves their end of world scenarios. Until they can separate out what is a natural process from the man made ones I have a hard time taking people like you seriously.
    The earth is 4.5 billion years old and you want to take 200-300 years of reliable data and extrapolate the theory of man made climate change as scientific fact. There are enough clear problems in the way mankind is living and effecting the planet that if we would just spend our time and energy dealing with those things could be so much better.

    And I would love to hear your scientific facts backing up the South’s failures and how they specifically are destroying the planet.

  25. Leif says:

    Bruce: I pointed out that that it was not just the south but humanities collective failure to use scientific understanding and awareness to make rational decisions in a timely fashion to avert disaster. I offered the video as evidence on numerous fronts, not only global warming, of this tendency. The oceans comprise ~ 71% of the earth surface and contrary to your statement of “over fishing the oceans in some places,” I believe the video was quite clear in stating that the oceans are over fished in all places with no meaningful mitigation strategies being enacted world wide. On the contrary we continue to actively alter the ocean chemistry to assure complete eradication of all shell life forms that comprise the base of the food chain. There is NO mitigation to alter this trend but stopping CO2 production. Yes, Nature can and will adjust but the Oceans will be a far different environment and you can be sure that it will not be conducive to supporting the population density envisioned. That would include you and yours.

    Science is telling us that the evidence is 95% sure that our present trajectory is on the course projected. If science told you that your next car outing had a 95% chance of a fatale crash would you take that ride?
    Do you need 100% assurance that your plane will drop out of the sky 45 minutes after takeoff before you will seek other modes of transportation to your destiny? Have you such faith in science that since your destination is 44 minutes away it is some one else’s problem?