NOAA: Researchers offer new insights into predicting future droughts in California

Natural cycles, sea surface temperatures found to be main drivers in ongoing event

According to a new NOAA-sponsored study, natural oceanic and atmospheric patterns are the primary drivers behind California’s ongoing drought. A high pressure ridge off the West Coast (typical of historic droughts) prevailed for three winters, blocking important wet season storms, with ocean surface temperature patterns making such a ridge much more likely. Typically, the winter season in California provides the state with a majority of its annual snow and rainfall that replenish water supplies for communities and ecosystems.

Further studies on these oceanic conditions and their effect on California’s climate may lead to advances in drought early warning that can help water managers and major industries better prepare for lengthy dry spells in the future.

“It’s important to note that California’s drought, while extreme, is not an uncommon occurrence for the state. In fact, multi-year droughts appear regularly in the state’s climate record, and it’s a safe bet that a similar event will happen again. Thus, preparedness is key,” said Richard Seager, report lead author and professor with Columbia University’s Lamont Doherty Earth Observatory.

This report builds on earlier studies, published in September in the Bulletin of the American Meteorological Society, which found no conclusive evidence linking human-caused climate change and the California drought. The current study notes that the atmospheric ridge over the North Pacific, which has resulted in decreased rain and snowfall since 2011, is almost opposite to what models project to result from human-induced climate change. The report illustrates that mid-winter precipitation is actually projected to increase due to human-induced climate change over most of the state, though warming temperatures may sap much of those benefits for water resources overall, while only spring precipitation is projected to decrease.

Folsom Lake, 2011

(Credit: CA Dept of Water Resources)

Folsom Lake, 2014

(Credit: CA Dept of Water Resources)

The report makes clear that to provide improved drought forecasts for California, scientists will need to fully understand the links between sea surface temperature variations and winter precipitation over the state, discover how these ocean variations are generated, and better characterize their predictability.

This report contributes to a growing field of science-climate attribution-where teams of scientists aim to identify the sources of observed climate and weather patterns.

“There is immense value in examining the causes of this drought from multiple scientific viewpoints,” said Marty Hoerling, report co-author and researcher with NOAA’s Earth System Research Laboratory. “It’s paramount that we use our collective ability to provide communities and businesses with the environmental intelligence they need to make decisions concerning water resources, which are becoming increasingly strained.”

To view the report, visit:

82 thoughts on “NOAA: Researchers offer new insights into predicting future droughts in California

  1. Thanks, Anthony, that helps to clarify matters a great deal! Here’s hoping that you and your fellow Californians are treated to a nice, regular rainfall and snowfall in the mountains!! Cheers, Charles the DrPH

    • Careful what you wish for Charles.
      CA now has a storm advisory, for an intense winter storm due to arrive Wed/Thurs (Dec. 10/11), with up to 4 inches of rain in urban areas, and up to 8 inches in the coastal mountains. Wind advisory says 30-40 mph in the urban areas, and possibly >60 mph in the coastal range.
      We’ve had a reasonable amount of rain already in December, so the ground is wet. If the storms hits as expected, there will be plenty of runoff and some local flooding.
      So far things are shaping up to a wet Winter. No promises, but the drought may be over for now.

  2. What difference will being able to predict droughts in California make when the state’s activists and brilliant legislators will stop nearly every single attempt to effectively prepare for it? Just asking.

    • “To provide improved drought forecasts for California, scientists will need to fully understand the links ..” What a deep new insight. Activists and brilliant legislators suspected it all the time.

    • Resourceguy
      December 8, 2014 at 10:40 am
      It will never pass the alarmist test for policy distortion purposes.

      Alarmists want to have their cake and eat it. They demand we listen to the science. When we do they don’t like the answers. Even when the IPCC tells them so based on observations.

      IPCC Fourth Assessment Report: Climate Change 2007
      Multiple proxies, including tree rings, sediments, historical documents and lake sediment records make it clear that the past 2 kyr included periods with more frequent, longer and/or geographically more extensive droughts in North America than during the 20th century (Stahle and Cleaveland, 1992; Stahle et al., 1998; Woodhouse and Overpeck, 1998; Forman et al., 2001; Cook et al., 2004b; Hodell et al., 2005; MacDonald and Case, 2005). Past droughts, including decadal-length ‘megadroughts’ (Woodhouse and Overpeck, 1998), are most likely due to extended periods of anomalous SST (Hoerling and Kumar, 2003; Schubert et al., 2004; MacDonald and Case, 2005; Seager et al., 2005), but remain difficult to simulate with coupled ocean-atmosphere models. Thus, the palaeoclimatic record suggests that multi-year, decadal and even centennial-scale drier periods are likely to remain a feature of future North American climate, particularly in the area west of the Mississippi River.

      Some warmists wonder why we don’t take their models seriously. The problem is choosing which model to base policy on.

      The Key Role of Heavy Precipitation Events in Climate Model Disagreements of Future Annual Precipitation Changes in California
      Climate model simulations disagree on whether future precipitation will increase or decrease over California, which has impeded efforts to anticipate and adapt to human-induced climate change……..Between these conflicting tendencies, 12 projections show drier annual conditions by the 2060s and 13 show wetter. These results are obtained from 16 global general circulation models downscaled with different combinations of dynamical methods…

  3. The current drought ‘severity’ might also have something to do with California’s population expanding 169% since 1970 while its seasonal water storage capacity expanded 40%. Self inflicted wound in a dry state with known periodic drought conditions.

  4. Nuccitelli has a different version of the Califonia drought story, mentioning Mann, tree rings, models, heatwaves, droughts, floods, and wildfires… general global warming doom and gloom.
    California just had its worst drought in over 1200 years, as temperatures and risks rise
    Global warming is playing havoc on extreme weather

      • He gets away with it because of dubious moderation at the Guardian.
        Nuccitelli lets some comments through, responds with half-truths (at best) and then deletes the referenced corrections without leaving a “this comment was removed…” stub.
        So he looks competent even though he knows he isn’t.

      • Easy. Politics like war and love have no rules.
        Nuccitelli in relation to science is incompetent and lacks integrity, qualities that are in high demand in politics.

      • Why not? He is a regular contributor for Guardian, they can’t become Nuccitelli-deniers. A newspaper going against its own editorial policy? No way.
        The Guardian also has readers, who expect and demand this kind of alarmism. Ignore readers’ interests for the sake of truth? Excuse me?

    • Not just the Guardian. My local paper had this on the front page with a big bold headline “Worst drought in 1,200 years”.
      From what I read the study only covered 3 years (2012-2014) which I assume are the rainfall years 2011/2012 thru 2013/2014 since the calendar year 2014 is not finished.
      They used tree rings to show while there were 37 other 3 year periods as dry or dryer, none were also as warm. From what I understand, tree rings are a poor proxy for temperatures as the making of the hockey stick showed us.
      So they use an extremely short time period and an extremely poor temperature proxy and translate that into a headline of worst drought in 1,200 years. Color me skeptical.

    • This report builds on earlier studies, published in September in the Bulletin of the American Meteorological Society, which found no conclusive evidence linking human-caused climate change and the California drought.

      This is the money quote from the paper … Nuccitelli instead invokes the climate spirits and says GAIA is troppo-mad with Kalifornia.

  5. Well they say a picture is worth a thousand words, so two pictures are worth two thousand words at least.
    I think I can use a few less than that.
    So I have a picture of a lake / reservoir full of water, and I have a different picture, different time, same place, of the same lake / reservoir devoid (almost) of any water.
    So what does that tell me ??
    Basically, it tells me they took a picture of a lake full of water, and a picture of the same lake with next to no water.
    Unfortunately, they didn’t say anything about what happened to the water in the lake between the two photographs.
    If they pumped all of that water down to SoCal, to fill a lake down there, like Pyramid lake for example; the message would seem to be:
    Yes we have water problems, but much of the problem is the politics of water, not the meteorology of water.

  6. I have the solution.
    Move to where they have water or desalinate some.
    Don’t like the desert or arid regions subject to drought? MOVE!

  7. So NOAA implies that climate change (i.e. warming) should tend to create more precipitation (RAIN!!!) for CA. Well what are we doing trying to stop it?!?! Aren’t we trying to get more reliable water sources in CA?

  8. What, you mean … this has NOT been worrrrrrrrrrrst drrrrrrrrrrrrrought innnnnnnnnnnn 1200 yearrrrrrrrrrrrrs?

    • Yes, it shows 33% of capacity but 68% of historical average and 40% more than at this time last year. So normally the reservoir is at 50% of capacity this time of year.
      I assume this reservoir is also used for flood control and is kept half full early in the rain season to prevent flooding. Later in the rain season Mar/Apr they probably allow it to fill closer to capacity for water storage.

  9. Odd, the ‘Nutter’ has a post today saying much the opposite. Who to believe? Who to believe?
    After all, alarmism is such a credible approach to persuasion.

  10. Is this a subliminal message to Jerry Brown to stop shuffling around to get Federal money for drought by way of global warming grand standing, and to stop using funds for unrelated projects like high-speed rail?

  11. Folks need to remember that California tends to drought when things are cooling. The ’70s had significant drought ( I learned to ski then and the mountains were nearly bare). There’s also a cyclical pattern layered onto it as the ocean warms / cools. Oh, and when it gets really bad, California has droughts that last a few hundred years and make the last 100 years look like a tropical rain forest in comparison.
    So just what will the PTB do when one of those returns (as it eventually will)? Hmmm? A flood of 1862 or a drought like did in the Anasazi are completely normal and expected events in California. They will happen again, and they are normal.
    What’s not normal is to say that normal rainfall in a year does not mean the drought has ended. With the new definition, you can be in 200% rain fall land and still be in a ‘drought’ since you have not had 100% recovery of all reservoirs (despite mismanagement). The traditional definition was “normal rain means a drought has ended”. The rest is just word games and “drought for political effect”…

  12. Maybe if governor moonbeam et al would stop worrying about the pygmy sphincter fish and actually listen to the grownups in the room that know what needs to be done, they could manage these situations better.

  13. On Thursday this week there is apparently going to be some serious rainfall throughout California, presumably one of the spin off effects of global warming, or not.

  14. Here is the headline for the same storm to hit British Columbia, just incredible. The CBC is in the same family as Australia’s ABC and England’s BBC.

  15. Same old, dependable Kevin Trenberth…
    […Kevin Trenberth, a researcher at the National Center for Atmospheric Research, praised some of the modeling techniques employed in the NOAA report but found the results unsurprising and incomplete.
    “I would contend that all droughts are largely natural in the sense that they arise from internal variability in the atmosphere-ocean systems,” Trenberth said. “But this study completely fails to consider what climate change is doing to water in California.”
    He continued: “[The report] completely misses any discussion of evapotranspiration and the increased drying associated with global warming. In a drought, where there is an absence of precipitation, it is easily demonstrated that the extra heat from global warming – the increasing heating from increased greenhouse gases, including carbon dioxide – enhances drying, increases risk of heat waves, and greatly increases risk of wild fire to a significant degree.”…]

  16. Check out the states on graph [own] water and rainfall for the northern and southern Sierra Nevada. The Northern tier is above the 75 year average and climbing. Also note that the 2011-2012 average is not far below the long term average, but is part of the ‘worst drought in 1,200 years’. What does a cherry look like after 1,200 years of drought? Just askin’.
    North —
    South —

  17. California precipitation has been covered earlier in WUWT, for example:
    In the above post, see my full reply, which I have quoted below without the 200+ years of Southern California rainfall data:
    Neil Jordan
    February 18, 2012 at 1:00 pm
    Dr. Christy: Thank you for your effort in bringing old records to light. There is another set of California records going back to 1769 that you might consider, related to the “Lynch Index” that was in the California Weather Sumary CD. Jim Goodridge sent me a California Weather CD in 2002 that contained the file “Lynch Index.xls” that tabulates Southern California rainfall from 1769-1770 to 1999-2000. The CA Weather CD updated to 2009 does not appear to have that file. The state climatologist at might provide some information.
    The Lynch Index was based on the August 1931 report, “Rainfall and Stream Run-Off in Southern California Since 1769″ by H. B. Lynch, for the Metropolitan Water District of Southern California. The report is available on-line at
    The Lynch Index spreadsheet correlates the index from the 1931 report with the rainfall record for Los Angeles. The index stops at 1930, and DWR did an extension to 2000. I did a linear regression analysis on the data, and also an extension (ref Bedient & Huber) of the data to present. Slopes of the regression lines are close to zero.
    [end quote]
    I might add that the 1931 Lynch Report shows that the water year with the lowest precipitation was 1789-1790.

    • It’s an interesting report Neil. The report written in Aug 1931 has a wealth of information. A few points I thought were relevant.
      “There has been no material change in the mean climatic conditions in Southern California in the last 162 years.”
      “About fifty-five per cent of all seasons yield less rainfall than the average rainfall record, and about one-third of the seasons show rainfall of less than eighty per cent of the average amount.”
      “The economic structure of Southern California has been tuned to a rainfall of somewhere near the normal amount. But orderly economic advancement is hindered in a thousand ways by periods of varying length in which the rainfall and consequently the recovery of water available for useful purposes decreases to a point below that required for the needs of a community.”
      I would surmise that nothing much has changed in the 83 years since this report was written and the current and future population has the same problems and climate conditions to deal with as those before it.

      • Richard G: You are correct about no change in the hydrologic picture. Dr. Christy’s work on Sierra snowpack supports that. The Lynch Report was prepared for the Metropolitan Water District of Southern California as part of its work for constructing the Colorado River Aqueduct a few years later. MWD provides water for most of the populated Southern California area, including part of San Diego’s water supply.
        What has changed is the population and the demands on a pioneering water system. That the system is still working successfully is testament to its conservative engineering design. I might add that the latest wrench in the gears is the Quantification Settlement Agreement, which you can look up on line. If you decide to get any deeper into the California or arid West water quagmires, heed the words attributed to Mark Twain: “Whiskey is for drinking. Water is for fighting over.”

      • Thank you for the link Neil as it was in pdf I saved it for a more proper reading when time permits. I might just have a look see at the QSA. Considering the current state of water affairs, it almost makes me long for the Zanja Hour or the Miners Inch.

    • It gets better. A few miles north in Huntington Beach, another desalination plant is hopefully crawling out of its regulatory quagmire. Re your your link’s statement “six years in the state’s permitting process”, look up “desalination is growth inducing” and browse the arguments that have been put up against desalination. In particular, look at P. Gleick’s Pacific Institute report at:
      Page 7 includes climate change. Page 6 includes an interesting statement that desalinated water is corrosive and damaging to water distribution systems. My understanding is that desalinated water is what Mother Nature evaporates from the sea surface and drops as rain which is put into water distribution systems. Maybe Gleick is looking at ultra-pure water, but that can be remedied by blending at the desalination plant before distributing to customers.

      • While pure water is an excellent solvent, I doubt that they would waste the energy to take the desalination to that level. On the other hand I wonder about the author’s motives!

  18. Good Lord. So how much of my paycheck supported this piece of kindergarten work? My grandparents, who were the offspring and descendants of Oregon Trail, Civil War, Revolutionary War, and pre-Revolutionary War pilgrims from Ireland are shaking their heads in their plain pine boxes, wondering just how much more stupid these Ivory Tower folks are becoming while they tell us of these [NOT] amazing discoveries. Neanderthals could have figured this one out, and probably did.

    • It may be common sense to you and not worth your money. However, it is important to have this voice heard. Witness the fits and mudslinging by Mann, Trenberth, et al in response. To have an NOAA-sponsored study take a rational, non-alarmist tone is both refreshing and important.

  19. Pamela, my ancestors (Bristow’s, Cooper’s, Ault’s) arrived to America from England and Germany during various periods in the 1700’s and would probably say it’s much ado about nothing.
    Heck, at one point in the early 1900’s they became climate refugee’s from the north and moved to Southern California.

  20. The link to the paper is broken….at least it’s not working for me… “Server Error in ‘/’ Application.
    The resource cannot be found.
    Description: HTTP 404. The resource you are looking for (or one of its dependencies) could have been removed, had its name changed, or is temporarily unavailable. Please review the following URL and make sure that it is spelled correctly.”
    Requested URL: /MAPP/californiadroughtreport.

  21. 4TimesAYear, if you go to this link for a SoCal newspaper you can clink on the lead story “Worse drought in 1,200 years” and there is a link marked “new scientific study” that will take you to the report in the AGU journal. It’s in pdf.

    • You should read the WUWT Policy page: (this will probably be deleted with all these terms included):
      “Certain topics are not welcome here and comments concerning them will be deleted. This includes topics on religion, discussions of barycentrism, astrology, aliens, bigfoot, chemtrails, 911 Truthers, Obama’s Birth Certificate, HAARP, UFO’s, Electric Universe, mysticism, and other topics not directly related to the thread.”

  22. ” scientists will need to fully understand the links between sea surface temperature variations and winter precipitation over the state, discover how these ocean variations are generated, and better characterize their predictability” – meaning you just can’t get it all from looking at the viewscreen of your video games.

  23. California’s drought is unfortunate, but it is not my fault. The guys that are using this to promote their forecasting and modelling are ambulance chasers. They love it when a disaster comes together.

  24. One of my friends who lives in Folsom (works at Intel in Folsom) told me last winter they were reducing the water levels so they could perform some maintenance work on the dam. Under those conditions, it doesn’t seem right to use it as evidence of drought. Doing a quick search shows that the dam is undergoing renovations to spillways that are expected to conclude in 2017. Upgrades are required to protect against 200 year floods. Maybe draining reservoir during a drought wasn’t the smartest way to do it.(

    • Well that would explain why they used that photo in their P.R. The propaganda that spews out from government agencies is beyond absurd and has been increasing in frequency.
      To me it’s a deceptive practice no different than a private company would be subject to civil penalties for doing the same.

  25. Having a bit of a dutch background, my first impression looking at those 2 pics I thought, ” why in the heck are they not dredging the silt “? Thus making the reservoir larger and using the removed soil to help down stream farms that have not seen natural replenishment from annual flooding of deltas etc. ( think Nile river stuff, you know, BEFORE the dumb dam that became useless as a irrigation and hydro experiment in the 60’s and 70’s?? Hey but what do I know or think, it might have even created a few jobs?

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