2011 Sets U.S. Record for Wet/Dry Extremes, Wettest Year in Philadelphia’s 2-Century Record, Wettest December Day in DC

Figure 1. Departure of precipitation from average for 2011, as of December 6, 2011.  Remarkably, more than half of the country (56%) experienced either a top-ten driest or top-ten wettest year, a new record. Image credit: NOAA/HPC.

— Dr. Jeff Masters in a WunderBlog repost (with added material at the end)

This year is now the wettest year in nearly 200 years of record keeping in Philadelphia, Pennsylvania. A large, wet low pressure system soaked the Northeast U.S. on Wednesday and early Thursday, bringing 2.31 inches of rain to the City of Brotherly Love, bringing this year’s precipitation total in Philly to 62.26 inches. This breaks the old yearly precipitation record of 61.20 inches, set in 1867. In a normal year, Philadelphia receives about 40 inches.

According to wunderground’s weather historian Christopher C. Burt, this is one of the most difficult U.S. city records to break, since rainfall records in Philadelphia go back to 1820. The only other sites with a longer continuous precipitation record in the U.S. are Charleston, SC (1738 -) and New Bedford, MA (1816 -).

20+ inches above average precipitation in Ohio Valley, Northeast

Philadelphia is not alone in setting a wettest year in recorded history mark in 2011. Over a dozen major cities in the Ohio Valley and Northeast have set a new wettest year record, or are close to doing so. Thanks to rains associated with this year’s tremendous tornado outbreaks in April in May, plus exceptionally heavy summer thunderstorm rains, combined with rains from Tropical Storm Lee and Hurricane Irene, portions of at least twelve states have seen rains more than twenty inches above average during 2011.

The fraction of the country covered by extremely wet conditions (top 10% historically) was 32% during the period January through November, ranking as the 2nd highest such coverage in the past 100 years. And if you weren’t washing away in a flood, you were baking in a drought in 2011–portions of sixteen states had precipitation more than twenty inches below average (Figure 1.)

The fraction of the country covered by extremely dry conditions (top 10% historically) was 22% during the period January through November, ranking as the 8th highest in the past 100 years. The combined fraction of the country experiencing either severe drought or extremely wet conditions was 56% averaged over the January – November period–the highest in a century of record keeping [see Figure 2 below].

Climate change science predicts that if the Earth continues to warm as expected, wet areas will tend to get wetter, and dry areas will tend to get drier–so this year’s side-by-side extremes of very wet and very dry conditions should grow increasingly common in the coming decades.

Figure 2. Percentage of the contiguous U.S. either in severe or greater drought (top 10% dryness) or extremely wet (top 10% wetness) during the period January – November, as computed using NOAA’s Climate Extremes Index. Remarkably, more than half of the country (56%) experienced either a top-ten driest or top-ten wettest year, a new record. Image credit: NOAA/NCDC.

Unofficial state yearly precipitation record set in Ohio
The Wilmington, Ohio NWS office announced last week that three stations in Southwest Ohio had unofficially broken the 140-year old state yearly precipitation record. Cheviot, Miamitown, and Fernbank have recorded 73.81″, 71.89″, and 70.85″, respectively so far in 2011, beating the old record of 70.82″ set at Little Mountain in 1870. According to wunderground’s weather historian Christopher C. Burt, the old record should be 72.08” at Mt. Healthy, Ohio in 1880.

Wunderground’s weather historian Christopher C. Burt summarizes the global weather extremes in November in his latest post.

— Jeff Masters

JR:   See two posts from last week by Capital Climate:

  1. Precipitation Records Broken Tennessee to New England
  2. Wettest December Day in DC History: In fact, Wettest Day During the Entire Cold Season (November-March) in DC History

Related Climate Progress Posts:

One of the opening statements, which I’m sure you’ve probably heard is “Well you can’t attribute a single event to climate change.” But there is a systematic influence on all of these weather events now-a-days because of the fact that there is this extra water vapor lurking around in the atmosphere than there used to be say 30 years ago. It’s about a 4% extra amount, it invigorates the storms, it provides plenty of moisture for these storms and it’s unfortunate that the public is not associating these with the fact that this is one manifestation of climate change. And the prospects are that these kinds of things will only get bigger and worse in the future.

21 Responses to 2011 Sets U.S. Record for Wet/Dry Extremes, Wettest Year in Philadelphia’s 2-Century Record, Wettest December Day in DC

  1. Joan Savage says:

    The US Weather Service’s Climate Prediction Center’s long term forecast for 2012 is mostly more of the same, though the Pacific Northwest might be colder and wetter, and the southern drought spread farther east and west. The maps say it better.

  2. joan Savage says:


    1000 meter wide seeping structures of methane
    fountains of methane to the atmosphere

    The Independent article mentions release of the findings at the AGU conference last week in San Francisco, but AGU didn’t have Semiletov or the topic of Arctic methane on the list of lectures.

  3. David B. Benson says:


  4. Spike says:

    Looks like we might need a geoengineering technique to remove methane – I understand hydroxyl radicals destroy it, and wonder if anyone is looking at that. Not desirable clearly but the sensible measures keep getting put off and the Arctic isn’t going to cut us any slack.

  5. Raul M. says:

    Do the blue areas of the map correspond to the jet stream bringing cold to mix with moist air for rain and snow fall?

  6. Lou Grinzo says:

    One of the things I constantly stress on those not engaged with the subject of climate change is that it invalidates a lot of our assumptions. Humanity builds a lot of infrastructure, from buildings to power plants to roads and vehicles, and in every case there is a list of assumptions about the surrounding environment for that object — what are the minimum and maximum temps?, how much cooling water at what temperature will be readily available for a power plant?, how high will a “really bad” storm surge be at this site?, etc.

    Climate change is rewriting the rules and changing some of the environmental characteristics that we implicitly assumed “would never change”. One of the broadest based impacts is already happening: We’ve had numerous instances in the last decade of power plants in the EU and the US being shut down completely or throttled back due to an insufficient volume of cooling water (or water too warm to be useful), as well as a reduction (25%, I think) in generated hydro power in China in 2010/2011, thanks to lower rainfall. We can expect more of the same.

  7. perceptiventity says:

    And we have just begun. I wonder how will this fall seeded winter crops will fare in 2012 USA harvest.

    And off-topic,sorry, but this methane news was reported on russian internet back on the 16th of october 2011 first.
    Semiletov for instance said: ” It is still too early to come to conclusions on our research in the Arctic. Сalculations on how the gigantic methane emissions will really affect Earth ecology will be ready in about half a year. Then papers with those will appear on the desks of major country leaders.”
    But the most disturbing information perfectly matches The Independent post and he underlines this in the end of the russian interview:” This being said some of the fountains reach gigantic sizes – up to akillomiter in diameter. This is absolutely unique event, which was discovered here for the first time.”
    And the guy has been working in the area for 20 odd years. From tens of miters to a kilometer… So how unique is that?
    I suggest Joe Romm does an interview with him at some point.

    No less disturbing and also off topic

    The work challenges the belief that fish, unlike organisms with shells or exoskeletons made of calcium carbonate, will be safe as marine CO2 levels rise.

  8. tpinlb says:

    What are the roles of La Nina/ENSO and the Pacific Decadal Oscillation in creating this pattern of weather in the United States? Is it true that strong La Nina events are correlated with drought in Texas and the southwest?

  9. BH says:

    It would be interesting to see the map drawn using the percentage difference of 2011 precipitation compared to recent mean precipitation. For example, show Philly as being (62.26-40)/40 = 55% above normal. I think this would make it easier to appreciate the magnitude of the anomalous precipitation amounts. For example, parts of Texas were ~20″ drier than normal this year, but is that 20″ out of a normal of 25″ or 60″?

  10. BA says:

    So The Independent made up the story?

  11. BA says:

    This article is also coming up in my google search. Any geo-engineering had well better take place with a global stand-down in CO2 emissions.

  12. climatehawk1 says:

    They don’t get called out here, so let me draw attention to a few seriously eye-popping numbers in the precipitation tables:

    Williamsport, PA, records since 1895: broke old record by 7.1 inches (11.5%).
    Harrisburg, PA, records since 1861: broke old record by 12.29 inches (20.5%).
    Binghamton, NY, records since 1890: broke old record by 16.61 inches (33.7%)
    Cleveland, OH, records since 1855: broke old record by 8.51 inches (15.8%)

    To me, these are far more impressive than Philadelphia breaking its old record by 1.7%.

  13. joan Savage says:

    I doubt that.
    Semiletov had previously told a Russian paper that the report was expected in April. If he and his colleagues presented informally at AGU they might not have been listed on the program.
    Wikipedia’s take on The Independent includes its billionaire Russian businessmen owners and its opposition to the Murdoch news media. It’s not an “Onion” type of media.
    It would be great if someone (!) could interview others on the Russian – US team now that the Independent had his exclusive.

  14. joan Savage says:

    Here’s a link to an announcement in October that had less detail, and the expectation of a publication in April.

  15. Michael T says:

    The Northeastern U.S. has recorded its wettest January-November period on record at 51.65″.

    As this NOAA graph shows, the trend in precipitation for the northeast region is increasing 4.62″ per century.

  16. joan Savage says:

    What is key is hearing a revised estimate that at least some areas of Arctic shelf methane releases had reached “a hundred times” what they expected based on previous field studies. I’m frustrated by the generality of the quote in the news article, because a sweeping statement is not characteristic of the more usually detailed work of Semiletov and his colleagues.

    In earlier work, estimates of methane release were calculated by locale and season, so it would be useful to see how the observed increased release in the area visited by the expedition in fall 2011 relates to the overall estimate of marine methane release in the Arctic.

    A reference is the 2010 peer-reviewed publication in Science:

    Natalia Shakhova, Igor Semiletov, Anatoly Salyuk, Vladimir Yusupov, Denis Kosmach, Organ Gustafsson

    Extensive Methane Venting to the Atmosphere from Sediments of the East Siberian Ice Shelf

    Science 327, 1246 (2010)
    DOI: 10.1126/science.1182221
    5 March 2010

    This article is available for personal use through google.

  17. BA says:

    Thanks Joan, that is all very helpful. I knew a little bit about the expedition before but the quotes in the Independent are stark and hair raising. I have to digest all this a bit. I am not a scientist but my reason plus intuitions is telling me this is very serious. We need to put on the brakes fast and get on with a post carbon would as I see it.

  18. Dr.A.Jagadeesh says:

    Is this an indication of Climate Change?

    Dr.A.Jagadeesh Nellore(AP),India

  19. Colorado Bob says:

    Tropical Storm Lee’s flood in Binghamton: was global warming the final straw?

    One of these disasters was the approximately $1 billion in damage due to flooding from Tropical Storm Lee, which brought torrential rains along a swath from Louisiana to New York in early September. Among the hardest hit cities was Binghamton, New York (population 47,000), where record rains due to the remnants of Tropical Storm Lee on September 8 brought a 1-in-200 to 1-in-500 year flood to the city’s Susquehanna River.

  20. Colorado Bob says:

    Binghamton’s 2nd 1-in-200-year+ flood in five years
    This year’s flood is the second 1-in-200 to 1-in-500 year flood in the past five years to hit Binghamton. On June 26 – 29, 2006, tropical moisture streaming northwards over a front stalled out over New York state brought over thirteen inches of rain to portions of southern New York. The Susquehanna River swelled to record levels, triggering devastating flooding that cost at least $227 million. In Binghamton, the Susquehanna River crested eleven feet over flood stage, the greatest flood since records began in 1846. The flood walls protecting Binghamton were overtopped by a few inches, allowing water to pour into the city and cause tens of millions of dollars in damage. This flood is another example of a case where global warming may have been “the straw that broke the camel’s back”, allowing the flood walls to be overtopped by a few inches. While it is not impossible that the 2006 flood and the 2011 flood could have occurred naturally so close together in time, such a rare double flood has been made more likely by the extra moisture added to the atmosphere due to global warming.