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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 Niño events.112 [Kunkel et al., 2008]

Then we have this apparently as yet unpublished research presented by Dr James Overland of the NOAA/Pacific Marine Environmental Laboratory at the recent International Polar Year Oslo Science Conference (IPY-OSC) where he was chairing “a session on polar climate feedbacks, amplification and teleconnections, including impacts on mid-latitudes.” “Cold and snowy winters will be the rule, rather than the exception,” says Dr James Overland…. Continued rapid loss of sea ice will be an important driver of major change in the world’s climate system in the years to come…. “While the emerging impact of greenhouse gases is an important factor in the changing Arctic, what was not fully recognised until now is that a combination of an unusual warm period due to natural variability, loss of sea ice reflectivity, ocean heat storage and changing wind patterns working together has disrupted the memory and stability of the Arctic climate system, resulting in greater ice loss than earlier climate models predicted,” says Dr Overland. “The exceptional cold and snowy winter of 2009-2010 in Europe, eastern Asia and eastern North America is connected to unique physical processes in the Arctic,” he says.

Even though these storms occurred during warmest winter on record, I think the best way to talk about it until Overland publishes his work is the way NCAR’s Kevin Trenberth did on NPR (audio here): RENEE MONTAGNE, host:  With snow blanketing much of the country, the topic of global warming has become the butt of jokes. Climate skeptics built an igloo in Washington, D.C. during last weeks storm and dedicated it to former Vice President Al Gore, who’s become the public face of climate change. There was also a YouTube video called “12 Inches of Global Warming” that showed snowplows driving through a blizzard.For scientists who study the climate, it’s all a bit much. As NPRs Christopher Joyce reports, they’re trying to dig out. CHRISTOPHER JOYCE: Snowed-in Washington is where much of the political debate over climate change happens. So it did not go unnoticed when a Washington think-tank that advocates climate action had to postpone a climate meeting last week because of inclement weather. That kind of irony isnt lost on climate scientists. Most don’t see a contradiction between a warming world and lots of snow. Heres Kevin Trenberth, a prominent climate scientist at the National Center for Atmospheric Research in Colorado. Mr. KEVIN TRENBERTH (Scientist, National Center for Atmospheric Research): The fact that the oceans are warmer now than they were, say, 30 years ago, means there’s about, on average, 4 percent more water vapor lurking around over the oceans than there was, say, in the 1970s. JOYCE: Warmer water means more water vapor rises up into the air. And what goes up, must come down. Mr. TRENBERTH: So one of the consequences of a warming ocean near a coastline like the East Coast and Washington, D.C., for instance, is that you can get dumped on with more snow, partly as a consequence of global warming. JOYCE: And Trenberth notes that you don’t need very cold temperatures to get big snow. In fact, when the mercury drops too low, it may be too cold to snow. There’s something else fiddling with the weather this year: a strong El Nino. That’s the weather pattern that, every few years, raises itself up out of the western Pacific Ocean and blows east to the Americas. It brings heavy rains and storms to California and the South and Southeast. It also pushes high-altitude jet streams farther south, which brings colder air with them. Trenberth also says El Nino can lock in weather patterns like a meteorological highway, so that storms keep coming down the same track. True, those storms have been big ones – record breakers. But meteorologist Jeff Masters, with the Web site Weather Underground, says it’s average temperatures — not snowfall — that really measure climate change. There’s more water vapor lurking around the oceans, and whatever the proximate cause of any one snow storm, there is little doubt that global warming means the overwhelming majority of East Coast storms will be sweeping in more moisture and dumping it on the ground.

"There has not been a seasonal forecast of 23 storms put out for this country before," said Holland.  Like forecasters from NOAA and elsewhere (see More pre-season predictions of a very active Atlantic hurricane season, at the WunderBlog for a summary of forecasts), Holland cited high SSTs as a principal factor underlying his assessment. The SSTs during the first month of the hurricane season did nothing to diminish concerns.  As the figure below indicates, high SSTs characterized the tropical Atlantic in June, with many areas again seeing record high temperatures for the month. 

"So what’s happening?" asks Holland.  "Well it’s a combination of global warming and natural variability."

This is consistent with research results published in Geophysical Research Letters on 29 April 2010.  In Is the basin-wide warming in the North Atlantic Ocean related to atmospheric carbon dioxide and global warming?, Chunzai Wang and Shenfu Dong of NOAA's Atlantic Oceanographic and Meteorological Laboratory, conclude that "both global warming and AMO [Atlantic multidecadal oscillation] variability make a contribution to the recent basin-wide warming in the North Atlantic and their relative contribution is approximately equal."

The vineyard also escaped the effects of the long, cold winter, he said: “We’ve been very lucky in this corner of the country. With the frosts in April and early May we got down to minus two very close to the buds being frosted off the vines. But not quite.” Now, Mr Barnes said he was hoping the weather stayed dry for the harvest at the end of September. Apples growers have also enjoyed the hot, sunny weather, but said the recent downpours were welcome. Sarah Calcutt, business development manager at Norman Collett, which markets English fruit from its base in Paddock Wood, said the extra light and warmth had been great for Rubens, a new variety of apples. “I’ve been out looking at orchards today with the National Fruit Show president and we’ve been particularly looking at Rubens. “We do not know if it will be a bumper crop yet because they won’t be picked until to September, but from an apple’s perspective the heat and sunshine in particular are great. “Photosynthesis is better with good light because it seeds the tree really well and gives it good energy for feeding themselves next year. A lot of day light hours are wonderful. “We’ve just had rain in time. One of the farmers who has no irrigation system said this bit we’ve just had came just in time for his young trees, which were starting to look a bit stressed. So the recent downpours have been fantastic.” However, organic fruit farmer Mrs Martin said that it had been a bad year for some fruits. “Raspberries are not looking very good this year. It was too hot for them and they were cooking on the plants,” she said. “But a little rain does everything good.” Dr Chris Atkinson, head of science at East Malling Research Centre, which has been collecting climate data since 1913, said the climate was a big determinate when growing fruit because temperature and rainfall had a big impact on crops. The climate data shows that the seasons have been getting longer and the winters are getting milder. “We can even answer sceptics about climate change – no one can argue that climatic data shows it is changing,” he said.

The centre has recorded increasingly milder winters and longer seasons. Dr Atkinson said the changing temperature should be used as an opportunity to explore new crops and spoke about someone who had successfully grown a banana outside in Cornwall.

“Apricots and nectarines on a commercial scale we believe will achieve economic gain in the UK rather than just surviving.” The centre is currently trialling hardy kiwis to see whether they can be grown as a crop.

Speaking about his own cherry trees in his garden, he said that this year they had produced more fruit than over the last 15.

“In Colorado, we get our wind from the west,” he explained. “Canada gets its wind from the east. Where the wind belts rub against each other – it causes friction. As friction occurs, it creates waves in the atmosphere. Waves create frontal systems. These frontal systems are most noticeable during the change of seasons, which is also when we get our biggest storms, particularly in spring and fall.” Fox concluded that climate change is tipping the balance toward a battle of heat and cold. “Storms, created when frontal systems collide, are the atmosphere’s way of dealing with differences in temperature,” he said. “The atmosphere is attempting to balance the energy and equalize the temperature with the air going from high pressure to low pressure.” Fox added that cold air is now coming further south than it used to and warm air is going further north than usual. “Wind is air trying to equalize pressure,” he said. The scientist then used the analogy of a runner eating a big bowl of pasta. “If he then downs a Red Bull, there is more energy in the system to fuel his run,” he said. This pasta analogy goes beyond the college classroom and has a practical and local effect as well. It can be applied to the recent wind and dust storms that have wreaked havoc on Durango locals and tourists alike. Bayfield motorcyclist Jeff Gilmore had his windshield sandblasted as he headed into Flagstaff recently. “Semis were lined up on the side of the road,” he said. “Foot high sand drifts progressed across I-89 from Page to Flagstaff.” Although he pulled down his full-face helmet and shut all the vents, Gilmore was still pounded. “Sand stuck to my chapstick and the fine grit got in my mouth,” he said.

Carlotta Haber and her daughter were sent 100 miles out of their way while driving from Durango to Sedona a few weeks ago. Just before Holbrook, Ariz., on I-40 West, a sign read, “Highway closed 43 miles ahead due to dust storm.” “I couldn’t see the car in front of me and big tumbleweeds were rolling at the car,” she said. These anecdotes are directly in line with scientific findings. In fact, the National Center for Atmospheric Research in Boulder has formulated global climate models forecasting that “all weather will get more extreme.” Storms are stronger than 20 years ago, according to NCAR, as the research center is predicting more precipitation per storm event, despite its forecast for fewer overall storms. Tim Foresman, former director of the United Nations Environmental program, explained, “These conditions are exactly what caused this past winter’s heavy snows in the East and the recent flooding in Tennessee. One was an extraordinary winter precipitation event and the other was a spring precipitation event.”

While these conditions may feel like an anomaly, research indicates that they are the logical result of changing conditions. National Climatic Data Center statistics reveal that in the last 30 years, the temperature has risen an average of 2 degrees in the United States. Since 1975, the average temperature in Colorado has increased by 2.28 degrees. The only two states whose temperatures have risen more are Utah, with a 2.43 degree increase, and Arizon,a with 2.79 degrees. A NASA report corroborates these findings. The report states that the last 12 months have been the warmest in at least 1,000 years. Foresman added, “The meteorological forecasts are based on prior weather patterns and may not be accurate without considering changes under way due to a warming climate. Forecasts are based on seasonal models from the immediate past and may not be a good indicator of the future due to changing climatic conditions.” His expertise has been extremely valuable to his sister-in-law, who just purchased property and is building a home in Durango. Counseling her on what to expect in the near future due to the changing patterns, she modified her construction plans.

Having recently experienced a blizzard in May in Santa Fe, Foresman stated the obvious. “The systems are all out of whack,” he said. “We’re going to be in for some interesting times. We can put our heads in the sand, or we can prepare.” In closing, Foresman remarked that the windiest days could be ahead for the Four Corners and Southwest and offered local residents a piece of advice. “If you have shutters on your windows, I suggest you make sure they’re functional and not decorative,” he said. “The winds aren’t going to go away until you turn the heat down.” •

The Alaska Interagency Coordination Center (AICC) reported yesterday: "Low winter snowpack in north-central Alaska, warm spring temperatures, and a lack of precipitation has driven fuel conditions to historical maximum levels in Tok and Fairbanks. Current conditions create the potential for rapid fire spread rates, crown fires, and higher intensity fires. A high pressure weather system centered over Alaska exacerbates the existing conditions." The National Weather Service this morning (30 May 2010) has issued "red flag" warnings for much of Alaska's interior, along with portions of the North Slope of the Alaska Range.  The warnings, which extend to late in the evening on 30 May, mean that "conditions are occurring or will occur which could lead to the development of large and dangerous fires."  See NOAA's Alaska Fire Weather for the latest watches and warnings. The AICC also said yesterday that  the current fire behavior and activity "is uncharacteristic for this time of year and is requiring a significant response statewide from Alaskan, Canadian and Lower-48 resources."  By late evening on 29 May, the last 5 available smokejumpers in Alaska were en route to a fire, emptying the smokejumper base in Fairbanks and bringing the total number of jumpers committed to fires to seventy.  The jumper base reported that none of the committed jumpers could be quickly demobilized from current fires to attack new fires.  With such "initial attack" firefighting resources constrained, fires will have more time to grow in size before firefighters arrive. According to today's Situation Report from the Alaska Interagency Coordination Center (AICC), there are 85 fires burning in the state.  A total of 193 fires have burned 98,163.3 acres so far this year.  The AICC Morning Highlights today said:  "Alaska is experiencing unprecedented fire activity for May that is more characteristic of extreme July conditions."  It added: "On a scale of 1-5, Alaska has now reached Preparedness Level 4. It means that multiple units are experiencing fire starts and there are several large, staffed fires. The probability of ignition is high, and conditions/ resistance to control are high to extreme, and weather conditions exist that promote fire growth. It also reflects the number of instate and out of state resources committed/required."

While researchers are confident that the higher temperatures and resulting changes in snowpack, Colorado River flow, vegetation mortality and wildfires are human-caused, they don't know whether the drought that has plagued the West for the last 10 years – the worst since record-keeping began – is because of humans, Overpeck said.

Many fishermen switched to lobster as winter flounder, a cold-water fish once abundant in fishing boat holds, declined. But lobster stocks are stressed in some areas now. Biologists on a multi-state Fisheries Commission committee have found that warmer waters, disease and fishing have depleted lobster stocks, and they recently recommended a five-year ban on lobstering from Cape Cod to Virginia.

"One of the grim realities of global warming is that it is bringing change to fisheries. There are going to be regime changes in the oceans and management is going to have to adapt to that,"

Greg Walinski believes he has seen first-hand the workings of warmer waters on fish stock. The 53-year-old Cape Cod fisherman used to hunt for large bluefin tuna. "In the '80s and '90s we would get 60 to 80 giant bluefin in a season," he said. "But we started to see less and less. It got to a point where it wasn't even worth going out. Most of the big fish are up in Canada," he said. "We get the little bluefin that used to be further south."

He switched to cod, but in what seems to be a repeat of the pattern, Walinski said he finds himself chasing the fish further and further out. He now travels 120 miles in a 35-foot boat - an arduous and somewhat dangerous commute - to reach Georges Bank for codfish.

regulators say they have seen little evidence of a similar rebound in cod on the George's Bank, and some other cold-water species, like winter flounder and pollock, remain low.

Migration is dwindling worldwide, Middleton says, and preserving some of the last large mammal migrations in North America has become a key conservation concern. Satellite images of where the elk roam now suggest what’s gone wrong with their migration, Middleton reported June 14 at the annual meeting of the American Society of Mammalogists. Images show that the period when grasslands are thriving and green with prime nutrition for grazers shrank by 40 percent between 1989 and 2009, he said. This premature grassland brownout fits with weather station data showing that over the past 21 years, the average July temperature in the migrants’ high-elevation summer range has risen more than 4 degrees Celsius, Middleton said. On top of that, nearly a decade of drought worse than the Dust Bowl dry-out has parched the Yellowstone region. In contrast, satellite images show little change in the greening of vegetation at the lower elevation, Middleton said. Elk remaining there not only have a more stable summer food source, but can nip over to some scattered agricultural outfits to take advantage of irrigated vegetation.

The BMC data was also corroborated by a paper presented on ‘Mumbai’s urban flooding vulnerability: preparedness and mitigation’ by IIT scientist Kapil Gupta.In his paper, Gupta said that 50% of the annual rains was received in 2-3 events