What Does the Peer-Reviewed Literature Say About Trends in East Coast Winter Storms?


The image above comes from a 2001 paper by Hirsch et al. (here in PDF) titled, An East Coast Winter Storm Climatology. The top curve shows all East Coast winter storms, and the bottom shows the most intense storms. for the period 1948 to 1997.

As the figure implies, they concluded in that analysis:

the frequency of ECWS show a downward tendency over the study period but at insignificant levels. One test found a decreasing trend in strong ECWS significant for an alpha = 0.10.

So there was no trend 1948 to 1997, or a slightly downward trend. This is interesting because over the latter half of that period one analysis (Willett et al. 2010) found an increase in the water content of the lower atmosphere over the US East Coast. So those who argue for a simple relationship between increasing water content of the atmosphere and storm strength, data do not support such a claim over this multi-decadal period, in this region.

In 2010 Frankoski and DeGaetano published an update to Hirsh et al. 2001, extending data through 2006. They concluded:

No significant time-dependent trends were identified for precipitation or snowfall from East Coast Winter Storms or for the percentage of precipitation or snowfall from East Coast Winter Storms.

Such research is likely why the IPCC AR5 concluded in 2013:

In summary, confidence in large scale changes in the intensity of extreme extra-tropical cyclones since 1900 is low.

What that means in climate-speak is that the detection of trends in winter storms has not been achieved. It also means that the IPCC has not attributed any trends to human influences. Detection and attribution are explained in some detail in my recent book.

You can of course find fringe views on both detection and attribution out there on the internet (carefully cherry picked).  There are also plenty of smart folks trying to do their own analyses without referencing the IPCC or the peer reviewed literature on the subject. Minority views and amateurs are legitimate and worth hearing, as they can add valuable new perspectives. But if these folks really wanted to contribute to scientific understandings they should seek to publish their alternative theories in the peer reviewed literature.

No one – least of all those who consider themselves professional journalists – should confuse these alternative perspectives for what is found in the peer-reviewed literature and the assessments of the IPCC.

For further reading, see Vose et al. 2014 and Wang et al. 2008.

12 thoughts on “What Does the Peer-Reviewed Literature Say About Trends in East Coast Winter Storms?

  1. In a comment widely cited by the media from his Climate Nexus press release linked above, Penn State’s Michael Mann, said:

    “The U.N. Intergovernmental Panel on Climate Change has found that Nor’easters like this one may grow stronger w/ human-caused climate change, as they are driven by the contrast between cold Arctic air masses and ever-warming ocean surface temperatures.”

    I have looked at the IPCC AR5 and every statement that it made on winter storms and extratropical cyclones, and in fact it says the opposite of what Mann has claimed, with frequency expected to decline and no consensus on intensity:

    “In the NH winter (Figure 12.20a, b), the CMIP5 multi-model ensemble shows an overall reduced frequency of storms and less indication of a poleward shift in the tracks. . . Substantial uncertainty and thus low confidence remains in projecting changes in NH winter storm tracks, especially for the North Atlantic basin.”
    http://ipcc.ch/pdf/assessment-report/ar5/wg1/WG1AR5_ALL_FINAL.pdf at p. 1074

    “There is general agreement that there will be a small global reduction in ETC numbers (Ulbrich et al., 2009). In individual regions there can be much larger changes which are comparable to natural variations, but these changes are not reproduced by the majority of the models (e.g., Donat et al., 2011). ETC intensities are particularly sensitive to the method and quantity used to define them, so there is little consensus on changes in intensity (Ulbrich et al., 2009). While there are indications that the absolute values of pressure minima deepen in future scenario simulations (Lambert and Fyfe, 2006), this is often associated with large-scale pressure changes rather than changes in the pressure gradients or winds associated with ETCs (Bengtsson et al., 2009; Ulbrich et al., 2009; McDonald, 2011). The CMIP5 model projections show little evidence of change in the intensity of winds associated with ETCs (Zappa et al., 2013b).”
    at p. 1252

    Mann is of course welcome to express his views on the science of extremes. However, his characterization of the IPCC in support of those views is in error. Mann owes the reporters that he has punk’d an apology.

    Liked by 1 person

    1. Are you then, er, now, a “denier” of climate science..?

      (citing support from the IPCC)


      1. Mann is quoting AR4, but Roger is using AR5. AR5 states in several sections, that AR4 results are “probably overstated”.

        The Yale posting says AR5 is more “wary” than AR4.


        So, Roger uses up to date results, which specifically states AR4 is over cooked in places, and Mann uses something from 2007, when a much newer result is available. I believe this is called cherry-picking.

        I know who I believe. And its not Mikey….

        I expect you will apologize to Roger?


  2. I have lived Northern NJ all my life. I’m not a meteorologist but we seem to different types of storms here. There are the ones that come up the coast and on classic north easters so influence by the ocean. Then there are the storms that come across the continent. Finally there mixture of the 2.


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