An amazing, though clearly little-known, scientific fact: We get more snow storms in warm years!

Scientists have been predicting for decades that increased greenhouse gas emissions would lead to an increase in many kinds of extreme weather events, especially more intense precipitation and more brutual heat waves.  So it’s not a big shock that what is likely to be the hottest year on record has witnessed so many blow-out extreme weather events from Nashville to Moscow to Pakistan — see NASA’s Hansen: Would recent extreme “events have occurred if atmospheric carbon dioxide had remained at its pre-industrial level of 280 ppm?” The “appropriate answer” is “almost certainly not.”

Indeed, “The first nine months of the year have seen the highest number of weather-related events since Munich Re started keeping records,” according to Dr. Peter Hoeppe, Head of the Geo Risks Research Department at Munich Re.  He said “that a clear pattern of continuing global warming was contributing to the natural disasters.”

Recently, some December precipitation records have been falling — in Seattle and Portland, Oregon.  These weren’t the 1000-year extremes that I typically write about — or the statistical aggregation of U.S. record highs vs. record lows — but I merely point them out because the anti-science crowd, led by discredited former TV weatherman Anthony Watts, persists in shouting about precipitation primarily when it comes down in solid form, even when it isn’t record-breaking.  Snowstorms are pretty much all the disinformers have left to shout about now, at least to those who don’t pay close attention to the science.

Since we’re entering the snowy season and can expect a blizzard of disinformation in this area, I’m updating this post from February, “We get more snow storms in warm years!

Everybody talks about the weather, but few read the scientific literature about it.

The anti-science crowd has been doing a killer job pushing the myth that the big recent snowstorms somehow undercut our understanding of human-caused global warming.  But aside from the fact the precipitation isn’t temperature, it turns out that the “common wisdom” the disinformers are preying on “” lots of snow means we must be in a cold season “” isn’t even true.

Let’s look at the results of an actual, detailed study of “the relationships of the storm frequencies to seasonal temperature and precipitation conditions” for the years “1901-2000 using data from 1222 stations across the United States.”  The 2006 study, “Temporal and Spatial Characteristics of Snowstorms in the Contiguous United States”  (Changnon, Changnon, and Karl [of National Climatic Data Center], 2006) found we are seeing more northern snow storms and that we get more snow storms in warmer years:

The temporal distribution of snowstorms exhibited wide fluctuations during 1901-2000, with downward 100-yr trends in the lower Midwest, South, and West Coast. Upward trends occurred in the upper Midwest, East, and Northeast, and the national trend for 1901-2000 was upward, corresponding to trends in strong cyclonic activity”¦..

Results for the November-December period showed that most of the United States had experienced 61%- 80% of the storms in warmer-than-normal years. Assessment of the January-February temperature conditions again showed that most of the United States had 71%-80% of their snowstorms in warmer-than-normal years. In the March-April season 61%-80% of all snowstorms in the central and southern United States had occurred in warmer-than-normal years”¦. Thus, these comparative results reveal that a future with wetter and warmer winters, which is one outcome expected (National Assessment Synthesis Team 2001), will bring more snowstorms than in 1901-2000. Agee (1991) found that long-term warming trends in the United States were associated with increasing cyclonic activity in North America, further indicating that a warmer future climate will generate more winter storms.

This year, of course, is poised to be the hottest year on record, so big snowstorms wouldn’t be terribly surprising, at least for those who follow the scientific literature.

The U.S. Global Change Research Program (USGCRP) U.S. Climate Impacts Report from 2009 reviewed that literature and concluded:

Cold-season storm tracks are shifting northward and the strongest storms are likely to become stronger and more frequent.

Large-scale storm systems are the dominant weather phenomenon during the cold season in the United States. Although the analysis of these storms is complicated by a relatively short length of most observational records and by the highly variable nature of strong storms, some clear patterns have emerged.112 [Kunkel et al., 2008]

Storm tracks have shifted northward over the last 50 years as evidenced by a decrease in the frequency of storms in mid-latitude areas of the Northern Hemisphere, while high-latitude activity has increased. There is also evidence of an increase in the intensity of storms in both the mid- and high-latitude areas of the Northern Hemisphere, with greater confidence in the increases occurring in high latitudes.112 [Kunkel et al., 2008] The northward shift is projected to continue, and strong cold season storms are likely to become stronger and more frequent, with greater wind speeds and more extreme wave heights.68 [Gutowski et al, 2008]


The northward shift in storm tracks is reflected in regional changes in the frequency of snowstorms. The South and lower Midwest saw reduced snowstorm frequency during the last century. In contrast, the Northeast and upper Midwest saw increases in snowstorms, although considerable decade-to-decade variations were present in all regions, influenced, for example, by the frequency of El Ni±o events.112 [Kunkel et al., 2008]

There is also evidence of an increase in lake-effect snowfall along and near the southern and eastern shores of the Great Lakes since 1950.97 [Cook et al, 2008]  Lake-effect snow is produced by the strong flow of cold air across large areas of relatively warmer ice-free water. As the climate has warmed, ice coverage on the Great Lakes has fallen. The maximum seasonal coverage of Great Lakes ice decreased at a rate of 8.4 percent per decade from 1973 through 2008, amounting to a roughly 30 percent decrease in ice coverage (see Midwest region). This has created conditions conducive to greater evaporation of moisture and thus heavier snowstorms. Among recent extreme lake-effect snow events was a February 2007 10-day storm total of over 10 feet of snow in western New York state. Climate models suggest that lake-effect snowfalls are likely to increase over the next few decades.130 [Burnett et al., 2003] In the longer term, lake-effect snows are likely to decrease as temperatures continue to rise, with the precipitation then falling as rain.129 [Kunkel et al, 2002].

Finally, the words of Dr. Kevin Trenberth, head of the Climate Analysis Section at the National Center for Atmospheric Research, in the NY Times this August bear repeating:

“It’s not the right question to ask if this storm or that storm is due to global warming, or is it natural variability. Nowadays, there’s always an element of both.”

This is cross-posted at Science Progress, CAP’s online publication about progressive science and technology policy.

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14 Responses to An amazing, though clearly little-known, scientific fact: We get more snow storms in warm years!

  1. paulm says:

    “The first nine months of the year have seen the highest number of weather-related events since Munich Re started keeping records,”

    By this measurement I would bag it as the warmest year since records began.
    Now lets see what the instrument measurements say….

  2. Prokaryotes says:

    The difference about this report, the last time it came up during february 2010.

    This was December 2009

    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.

    The temporal distribution of snowstorms exhibited wide fluctuations during 1901–2000, with downward 100-yr trends in the lower Midwest, South, and West Coast. Upward trends occurred in the upper Midwest, East, and Northeast, and the national trend for 1901–2000 was upward, corresponding to trends in strong cyclonic activity.

    Finally, we have the 2009 government report on U.S. climate impacts, which concluded:

    – “Cold-season storm tracks are shifting northward and the strongest storms are likely to become stronger and more frequent.”

    – “In winter and spring, northern areas are expected to receive significantly more precipitation than they do now, because the interaction of warm and moist air coming from the south with colder air from the north is projected to occur farther north than it did on average in the last century.

    This was January 2010

    Preparing For Frankenstorms: “The most powerful low pressure system in 140 years of record keeping” slams the Southwest.

    The “strongest winter storm in at least 140 years,” swept through the Southwestern United States last week, “bringing deadly flooding, tornadoes, hail, hurricane force winds, and blizzard conditions.” Rain dumped on Los Angeles, San Diego, and Phoenix, as mountains received up to four feet of snow. Wind gusts exceeding 90 miles per hour, tornadoes, and water spouts spun off the monster storm. Over 159,000 people lost power in the storm’s wake. Meteorologist Dr. Jeff Masters wrote on Friday that the storm was “truly epic”:

    We expect to get powerful winter storms affecting the Southwest U.S. during strong El Niño events, but yesterday’s storm was truly epic in its size and intensity. The storm set all-time low pressure records over roughly 10 – 15% of the U.S.–over southern Oregon, and most of California, Nevada, Arizona, and Utah

    February 2010
    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.

    March 2010

    Global boiling: Freak storms on every continent
    Second known tropical cyclone forms in “cooler” South Atlantic, while Red River braces for fourth “ten-year flood” in a row!

    “I actually think the science around climate change is real. It is potentially devastating,” Obama told reporters Monday [March 24, 2009]. “If you look at the flooding that’s going on right now in North Dakota and you say to yourself, ‘If you see an increase of two degrees, what does that do, in terms of the situation there?’ That indicates the degree to which we have to take this seriously.“

  3. Just this morning on CNBC, a guest stock analyst (Jeff Saut of Raymond James) said he thought the outlook was favorable for the energy sector. The reason he gave was that the winter would be “unexpectedly cold” because the tropics are expanding.

  4. Garry Powell says:

    Another factor that adds to the increasing moisture in the air is the huge amount of water vapor that is discharged from the Cooling Towers in air conditioning systems in Hotels, large Condominiums, Shopping Centers and manufacturing facilities around the world. I have never seen an estimate of the amount that is discharged into the atmosphere, world wide, but it has to be huge, and it can be calculated.

  5. Lou Grinzo says:

    Speaking as someone who lives in that lake-effect snow area (on the south shore of Lake Ontario), I can tell you it’s real and it has almost everyone’s attention. That’s especially true this year, after the Lakes hit very high (record?) temps during the summer. People here (at least the ones paying attention) are hoping that the lakes cool down before we get wacked with a record storm.

    Another little oddity is where the “snow bands” fall. Around Rochester, if you’re very close to the lake you get much less snow than if you’re 10 miles, say, south and further from the lake. A lot of the moisture simply skips over the shore before falling out as snow. The “snow line” is around US 90, sometimes a little farther north, and we can get very dramatic differences in snowfall over short distances.

  6. Inverse says:

    Any wave pattern experiences extremes as it moves into another direction. The trick is to identify what the sign is. So is increased snow and more precipitation a sign of increased chaos due to climate warming or is it the start of the earths climate moving into a colder phase as happens every 30 or so years.

    Whatever man does to the climate the temp wave cycles will still happen and if they have not been factored into the models the next 30+ years could be very difficult to explain to a growing skeptical public why temperature is falling. The whole basis of CO2 increasing but temperature falling will be hard to justify and if CO2 drops then the argument is lost.

  7. Prokaryotes says:

    Winter Weather Shuts Down the Midwest

    Residents are surprised about how fast the snow piled up.

  8. rjs says:

    while i dont doubt the correlation, isnt it possible that snowy winters cause naturally warmer years, as the cloud cover holds the heat near the ground, while clear winters allow the ground heat to escape into the atmosphere?

  9. Rabid Doomsayer says:

    Drought and flood, drought and flood. The normal rainfall season is not so normal anymore. Is that our future; continuous near drought, broken only by flood?

    OK so papers only report the bad news, but throughout the world there has been a lot of bad news for farmers this year. That will be bad news for us, food prices will inevitably rise. I can forgo luxuries, but for the poor food is a luxury.

    Been reading the Progress Report/Wonk Room on the growing inequality in the US. Be scared, in the US the poor are armed.

  10. Paulm says:

    US is in for a surprise with peak oil prices and living in a snow bound area.

    The cost of clearing the snow/ice is going to be crippling in winter months. Another small but essential brick in the fabrick of a organized society crumbles.

    Power outages continue across Eastern Canada and schools remain closed in parts of Ontario while more than 1,000 plows worked through the night in Quebec.

  11. Paulm says:

    #9 rabid,

    We are seeing longer sustained warming trends especially during night times.
    The heat is sucking the moisture out of the soil due to this and it is playing havoc with farming.

    Southern Farmers Struggle With Drought In U.S.

    “Last year it wasn’t as dusty, it wasn’t as powdery,” he said.

  12. Mike says:

    The first link was referenced by Hansen in the second link. Both were interesting.

  13. riverat says:

    Garry Powell says: December 13, 2010 at 1:51 pm

    Another factor that adds to the increasing moisture in the air is the huge amount of water vapor that is discharged from the Cooling Towers in air conditioning systems in Hotels, large Condominiums, Shopping Centers and manufacturing facilities around the world.

    I doubt the water vapor emissions you mention amount to much compared to natural sources. They pale compared to the area of the ocean’s surface. Excess water vapor precipitates out of the atmosphere pretty fast. It could have an effect in the local region but not likely much worldwide.

  14. Paulm says:

    They nearly mention climate warming….

    Storms wreaking havoc across the world
    Drought-stricken countries across the Middle East had been praying for rain for weeks when the weather turned violent at the weekend, with at least five people killed as gale-force winds and torrential rain pounded the coastline.

    Weather warnings issued for half the country