Showing posts with label Jeff Masters. Show all posts

Paul Douglas, Jeff Masters: October 26, 2010, weather bomb breaks all time low pressure records


'Weather bomb' hits Midwest with power of major hurricane

by Joseph Romm, Climate Progress, October 27, 2010
My dad was the biggest Republican that ever walked the earth. He always said: “Actions have consequences.” To pretend that a 38% increase in greenhouse gases isn’t going to have any impact, that we can have our cake and eat it too, and smear it all over our face, and maybe have our grandchildren deal with the hangover, I think it is immoral.
That’s Minnesota meteorologist Paul Douglas in an exclusive interview with Brad Johnson about the “weather bomb” that just hit and the global warming deniers that populate his state.
Weather bomb
Visible satellite image of the October 26, 2010, superstorm taken at 5:32 p.m. EDT. At the time, Bigfork, Minnesota was reporting the lowest pressure ever recorded in a U.S. non-coastal storm, 955 mb. Image credit: NASA/GSFC.
But let’s start with meteorologist Jeff Masters, who puts this staggering superstorm in contextand examines the climate change angle:

The mega-storm reached peak intensity late yesterday afternoon over Minnesota, resulting in the lowest barometric pressure readings ever recorded in the continental United States, except for from hurricanes and nor’easters affecting the Atlantic seaboard. So far, it appears the lowest reading (not yet official) was a pressure of 28.20″ (954.9 mb) reduced to sea level reported from Bigfork, Minnesota, at 5:13 p.m. CDT. Other extreme low pressures from Minnesota during yesterday’s storm included 28.22″ (956 mb) at Orr at 5:34 p.m. CDT, 28.23″ at International Falls (3:45 p.m.), and 28.23″ at Waskuh at 5:52 p.m. The 28.23″ (956mb) reading from International Falls yesterday obliterated their previous record of 28.70″ set on Nov. 11, 1949, by nearly one-half inch of mercury–a truly amazing anomaly. Duluth’s 28.36″ (961 mb) reading smashed their old record of 28.48″ (964 mb) set on Nov. 11, 1998. Wisconsin also recorded its lowest barometric pressure in history yesterday, with a 28.36″ (961 mb) reading at Superior. The old record was 28.45″ (963.4 mb) at Green Bay on April 3, 1982. The previous state record for Minnesota was 28.43″ (963 mb) at Albert Lea and Austin on Nov. 10, 1998. 
Yesterday’s records in context
Yesterday’s 28.20″ (955 mb) low pressure reading in Minnesota breaks not only the 28.28″ (958 mb) previous “USA-interior-of-the-continent-record” from Cleveland, Ohio, during the Great Ohio Storm of Jan. 26, 1978 (a lower reading in Canada during this event bottomed out at an amazing 28.05″/950 mb), but also the lowest pressure ever measured anywhere in the continental United States aside from the Atlantic Coast. The modern Pacific Coast record is 28.40″ (962 mb) at Quillayute, Washington, on Dec. 1, 1987. An older reading, taken on a ship offshore from the mouth of the Umpqua River in Oregon during the famous “Storm King” event on January 9, 1880, is tied with yesterday’s 28.20″ (955 mb.)
 
The lowest non-hurricane barometric pressure reading in the lower 48 states is 28.10″ (952 mb) measured at Bridgehampton, New York (Long Island), during an amazing nor’easter on March 1, 1914 (see Kocin and Uccellini, “Northeast Snowstorms; Vol. 2, p. 324, American Meteorological Society, 2004).  The lowest non-hurricane barometric pressure reading from anywhere in the United States was a 27.35″ (927 mb) reading at Dutch Harbor, Alaska, on Oct. 25, 1977. The lowest hurricane pressure reading was the 26.34″ (892 mb) recorded in 1935 during the Great Labor Day Hurricane… 
… the famed storm that sank the ore carrier Edmund Fitzgerald in 1974, killing all 29 sailors aboard, was weaker than the current storm. Indeed, I wouldn’t want to be on a boat in Lake Superior today–sustained winds at the Rock of Ages lighthouse on Isle Royale were a sustained 68 mph, gusting to 78 mph at 3 a.m. EDT this morning! 
Yet Another Remarkable Mid-latitude Cyclone so far this Year!
Yesterday’s superstorm is reminiscent of the amazing low pressures reached earlier this year (Jan. 19-22) in the West, where virtually every site in California, Nevada, Utah, Arizona, southern Oregon, and southern Idaho–about 10–15% of the U.S. land area–broke their lowest on record pressure readings. However, the lowest readings from that event fell well short of yesterday’s mega-storm with 28.85″ (977 mb) being about the lowest recorded at any onshore site. 
Commentary
We’ve now had two remarkable extratropical storms this year in the U.S. that have smashed all-time low pressure records across a large portion of the country. Is this a sign that these type of storms may be getting stronger? Well, there is evidence that wintertime extratropical storms have grown in intensity in the Pacific, Arctic, and Great Lakes in recent decades. I discuss the science in detail in a post I did earlier this year. Here is an excerpt from that post: 
General Circulation Models (GCMs) like the ones used in the 2007 IPCC Assessment Report do a very good job simulating how winter storms behave in the current climate, and we can run simulations of the atmosphere with extra greenhouse gases to see how winter storms will behave in the future. The results are very interesting. Global warming is expected to warm the poles more than the equatorial regions. This reduces the difference in temperature between the pole and Equator. Since winter storms form in response to the atmosphere’s need to transport heat from the Equator to the poles, this reduced temperature difference reduces the need for winter storms, and thus the models predict fewer storms will form. However, since a warmer world increases the amount of evaporation from the surface and puts more moisture in the air, these future storms drop more precipitation. During the process of creating that precipitation, the water vapor in the storm must condense into liquid or frozen water, liberating “latent heat”–the extra heat that was originally added to the water vapor to evaporate it in the first place. This latent heat intensifies the winter storm, lowering the central pressure and making the winds increase. So, the modeling studies predict a future with fewer total winter storms, but a greater number of intense storms. These intense storms will have more lift, and will thus tend to drop more precipitation–including snow, when we get areas of strong lift in the -15 °C preferred snowflake formation region.
You can read more of the weather records smashed by this superstorm at Capital Climate.


Here is more of Brad Johnson’s Wonk Room post:
Fueled by fossil fuel pollution, an unprecedented, freak “land hurricane” swept through the continental United States, leaving a path of devastation from Saskatchewan to Texas — while the Republican Party has been taken over by a hurricane of science denial. Our destabilized climate system, supercharged with billions of tons of manmade global warming pollution, is unlike anything in the historical record. “Welcome to the Land of 10,000 Weather Extremes,” Minnesota meteorologist Paul Douglas gasped. 
“The storm is huge,” Peter Kimbell, emergency preparedness meteorologist for Environment Canada, said. “Much of North America is being affected by this storm. It’s covering millions of square kilometers.” 
Douglas found intensity of the “weather bomb” something “hard to fathom”:
“Yesterday a rapidly intensifying storm, a ‘bomb,’ spun up directly over the MN Arrowhead, around mid afternoon a central pressure of 953 millibars was observed near Orr. That’s 28.14″ of mercury. Bigfork, MN, reported 955 mb, about 28.22″ of mercury. The final (official) number may be closer to 28.20-28.22″, but at some point the number becomes academic. What is pretty much certain is that Tuesday’s incredible storm marks a new record for the lowest atmospheric pressure ever observed over the continental USA. That’s a lower air pressure than most hurricanes, which is hard to fathom.”
The storm front — also dubbed the “Chiclone” for the bizarreness of having a cyclone-like system over Chicago — drew its power from a sharp temperature contrast between record warmth in the southeastern United States and average cold in the north. Thus this record stormfront, though it exhibited hurricane-like power, is unlike actual hurricanes that derive their power directly from heat trapped in the ocean. 
In an exclusive interview with the Wonk Room, Douglas — a nationally renowned meteorologist from Minnesota — discussed this “unprecedented, historic storm” and the consequences for our nation of our artificially altered climate. “We have to get acclimated mentally and physically for this kind of world where these kinds of supercharged storms are more frequent,” he said, as the atmosphere continues to warm. When asked about the numerous conservative global warming deniers in his own state — gubernatorial candidate Tom Emmer, incumbent Rep. Michele Bachmann (R-MN), Congressional candidates Chip Cravaack and Randy Demmer— and across the nation, Douglas said he was “ashamed” of the Grand Old Party for ignoring the “writing on the wall”:
“I’m a recovering Republican, and I don’t recognize my party any more. I’m ashamed so many Republicans don’t recognize the science. The writing is on the wall.”
When asked if reducing global warming pollution is a moral challenge and not just an economic debate, he agreed strongly:
“My dad was the biggest Republican that ever walked the earth. He always said: “Actions have consequences.” To pretend that a 38% increase in greenhouse gases isn’t going to have any impact, that we can have our cake and eat it too, and smear it all over our face, and maybe have our grandchildren deal with the hangover, I think it is immoral.”
Douglas said that this election has “been corrupted with money,” as the “energy lobby is obviously well-funded and powerful, and nobody wants to make waves.”
Nobody wants to make waves — except of course this superstorm, which, as Masters noted, was stronger than “the famed storm that sank the ore carrier Edmund Fitzgerald in 1974, killing all 29 sailors aboard.”

Here are two posts on the connection between human-caused global warming and superstorms that have been devastating the nation and the world during what is likely to be the hottest year on record:
“Given the association of extreme weather and climate events with rising global temperature, the expectation of new record high temperatures in 2012 also suggests that the frequency and magnitude of extreme events could reach a high level in 2012. Extreme events include not only high temperatures, but also indirect effects of a warming atmosphere including the impact of higher temperature on extreme rainfall and droughts. The greater water vapor content of a warmer atmosphere allows larger rainfall anomalies and provides the fuel for stronger storms driven by latent heat.”
“I find it systematically tends to get underplayed and it often gets underplayed by my fellow scientists. Because 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.”
The past 12 months have been the hottest on record, according to NASA.  So perhaps it isn’t completely surprising that we are seeing these record-smashing deluges.  But the number of these beyond-extreme events just in the United States alone ought to make people take notice:
And, of course, another part of the world has been even more devastated by deluges and flooding, albeit while receiving only moderate attention in this country (see Juan Cole: The media’s failure to cover “the great Pakistani deluge” is “itself a security threat” to America).

And then there was the devastation to Russia, a country that always thought it was going to benefit from climate change:
This is all one big coincidence for the anti-science disinformers.  But for the rest of us, the really scary part is that we’ve only warmed about a degree Fahrenheit in the past half-century.  We are on track to warm nearly 10 times that this century (see M.I.T. doubles its 2095 warming projection to 10 °F — with 866 ppm and Arctic warming of 20 °F ).

In short, we ain’t seen nothing yet!

Link:  http://climateprogress.org/2010/10/27/strongest-storm-ever-recorded-in-the-midwest/#comment-303331

Jeff Masters: Potentially catastrophic Super Typhoon Megi approaching the Philippines




Potentially catastrophic Super Typhoon Megi approaching the Philippines
 

by Jeff Masters, Wunderblog, Wunderground, October 17, 2010
The world's strongest tropical cyclone of 2010 is Super Typhoon Megi, which intensified into an extremely dangerous Category 5 super typhoon with 180 mph winds this morning. We are fortunate to have a hurricane hunter aircraft in Megi, as part of the Interaction of Typhoon and Ocean Project (ITOP), which is studying how the ocean responds to typhoon growth and movement in the Western Pacific Ocean. As part of ITOP, a C-130 hurricane hunter aircraft was in Megi this morning, and measured some truly remarkable winds and pressures. At 8:09 a.m. EDT (12:09 UTC), the aircraft measured winds at flight level (8,000 feet) of 220 mph. The SFMR surface wind measurement instrument recorded surface winds of 186 mph in regions where heavy rain was not contaminating the measurement, but found surface winds of 199 mph in one region of heavy rain. Now, this measurement is considered contaminated by rain, but at very high wind speeds, the contamination effect is less important than at lower hurricane wind speeds, and it is possible than Megi's surface winds are close to a sustained 200 mph. This is supported by the flight level winds of 220 mph, which support surface winds of 199 mph, using the usual 10% reduction rule of thumb. The Hurricane Hunters measured a surface pressure of 893 mb at 12 UTC. This is a phenomenally low pressure, ranking Megi as the 20th strongest typhoon ever recorded in the Western Pacific. Only three Atlantic hurricane have been more intense than Megi--Wilma (2005) at 882 mb, Gilbert (1988) at 888 mb, and the 1935 Labor Day Hurricane, at 892 mb. Megi's intensity easily beats out 2010's other two Category 5 storms, March's Tropical Cyclone Ului in the South Pacific and the East Pacific's Hurricane Celia of June, which both peaked at 160 mph winds. It is still possible that Megi will intensify further, as wind shear is low, less than 10 knots, SSTs are very warm, and the ocean has a very high total heat content.

Figure 1. Visible satellite image of Megi taken by NASA's Terra satellite at 1 a.m. EDT, Sunday, October 17, 2010. Image credit: NASA.

Megi is poised to deal a devastating blow to the northern portion of the Philippines' Luzon Island early Monday morning. If the super typhoon's winds stay near 180 mph, the damage will be catastrophic in the regions where the eyewall makes landfall. The Philippines government is taking Megi very seriously, and has ordered evacuation of all low  lying regions in Megi's path. Equally dangerous will be Megi's torrential rains, which will likely be more than 12 inches over wide regions of northern Luzon, creating dangerous mudslides and life-threatening flash floods. Once Megi crosses Luzon, the storm is expected to re-intensify and hit the Chinese coast between Hainan Island and Hong Kong as a major typhoon on Friday. Storm chaser James Reynolds is in northeast Luzon, and will be shooting pictures and video that he will upload his website typhoonfury.com, and Twitter, @TyphoonFury.

Wunderground.com’s Jeff Masters: From ‘Mad Scientist Club’ to Leading Internet Site



by Julie Halpert, Yale Forum, September 21, 2010

ANN ARBOR, MI. — When Jeff Masters was 10, he helped launch the “mad scientist club” in his Birmingham, Michigan, school, writing a 100-page thesis based on observations from his telescope.
By the time he was 12, he was diligently tracking the strength of wind gusts from a weather station he had set up in his backyard. The Midwest’s extremely variable climate conditions intrigued him. “I was always interested in weather,” he says.
It’s the kind of story sure to sound familiar to many of today’s meteorologists, weathercasters … and just plain “weather geeks,” a term they use endearingly of course: Weather gets into their blood early in life, and it’s something they take with them long into their careers, whether specifically weather-related or not.
Wunderground.com’s Jeff Masters’ dream job — ‘the truth’ and presenting what he sees as the best science.
Today, at age 50, all-things-weather are his job and his passion. A co-founder of The Weather Underground (wunderground.com), Masters created most of the software that formats the National Weather Service data used on the website, and also the imagery on the tropical page. And as a blogger on that site, he’s also become a committed advocate for the need to address human-caused climate change.
As Masters sits before a huge screen displaying maps from his site in his Ann Arbor office, he’s dressed in stereotypical scientist garb: a casual shirt, khaki shorts, and knee-high white tube socks with black dress shoes. Photographs of two National Oceanic and Atmospheric Administration hurricane hunter airplanes hang on the wall, along with a certificate recognizing his service there.

From College Degrees to Hurricane Hugo Scare

After receiving his bachelors and masters degrees in meteorology from the University of Michigan, he says, he was “burnt out from school.” On a lark, he applied for a job with the hurricane hunters as a flight meteorologist for NOAA’s Aircraft Operations Center. From 1986 to 1990, he spent his time flying into the eye of hurricanes.
“It was a dream job” that satisfied his huge fascination with weather, he said: “What better way to seek out the most intense storms and most interesting weather phenomena?”
He relished the thrill of the experience, but a near brush with death, flying into September 1989’s Hurricane Hugo, gave him a fresh perspective. The team had underestimated the weather, expecting a weaker storm. “We shouldn’t have been in the eyewall of a category five hurricane,” Masters says, thinking back and adding that they hadn’t paid adequate attention to the warning signs.
The plane’s engine caught fire and there was extreme turbulence. But the pilot was able to keep control of the plane, allowing it to land safely. Masters decided that would be his last flight, and says now that he still suffers from lingering effects of the “traumatizing” experience.

Wunderground.com — 10 to 11 Million Page Views a Day

He returned to the University of Michigan in 1990 to get his PhD and developed an internet-based weather-education project, the precursor to The Weather Underground, which he co-founded with Perry Samson, his PhD advisor. The Weather Underground launched in 1995, becoming the first commercial internet weather service, and among the first using real-time features of the internet for weather education. Today, it’s the 80th largest site on the internet, getting between 10- and 11-million page views a day and 15-million unique users a month.
Masters considers this another dream job, not only creating the programming but expanding his role to blog and generate content for the website.
Masters reads plenty of other blogs, and is a fan in particular of John Cook’s blogs at skepticalscience.com/. He also frequents realclimate.org,climateprogress.org, and desmogblog.com, which he thinks does well at unveiling climate deniers’ public relations campaigns intended to counter climate change science.
Masters says his blogs don’t “trash people” or question their motivations. “I’m just speaking the truth as I see it,” and presenting the best science, he says.
Masters considers himself different from most meteorologists, many of whom he says are unreasonably skeptical of climate change science. He says he thinks their skepticism stems in part from bachelors degree meteorology students’ not being required to study climatology or climate science as part of their formal degree requirements.
Masters says he believes that the conclusions of the IPCC report are “genuine, valid, and probably understated.” And he is critical of what he sees as well orchestrated and well funded climate misinformation campaigns.
“They’re able to persuade even intelligent people with a background in meteorology” that climate change isn’t occurring, he said. “It’s going to be a terrible wake-up call when the climate becomes unstable, and we’ll kick ourselves for being resistant to cutting our use of fossil fuels.”
He’s shared these views in his blogs, not surprisingly leading to hundreds of “hate e-mails” a year. Critics call him biased and chastise him for defending scientists named or involved in last fall’s hacked e-mails controversy at the University of East Anglia in the U.K. While he respects the right of these people to voice their point of view, he doesn’t pull punches: “The ignorance and greed that human society is showing in this matter will be to our ultimate detriment and possible destruction,” he says.
He urges his 14-year-old daughter to educate herself on climate change. “It will be the defining issue of their generation,” he says, though he admits these pleas fall on unconcerned ears for now, as she still has “one foot in the world of childhood.”
Masters works two days a week from his rural home, a half hour from his Ann Arbor office. During the hurricane season, he works every day. He’s financially stable enough to retire, but he says he has no plans of slowing down. Though marriage and a child and that earlier Hurricane Hugo scare have tamed any desires to fly into the eye of a hurricane, he says there is much left to do.
“There’s too much of a need for my skills now,” he says. He plans to continue being “a spokesperson for the best science we have on what the planet is doing and where’s it is headed.”
Author
Julie Halpert is a Michigan-based freelancer who has been covering environmental issues for the past 18 years for many outlets, including Newsweek, 
The New York Times and public radio. She also teaches an environmental journalism class at the University of Michigan.

"Heavy snowfall in a warming world" by Dr. Jeff Masters in his Wunderblog

Dr. Jeff Masters' WunderBlog 





 by JeffMasters,  February 8, 2010

A major new winter storm is headed east over the U.S., today, and threatens to dump a foot or more of snow on Philadelphia, New York City, and surrounding regions Tuesday and Wednesday. Philadelphia is still digging out from its second top-ten snowstorm of recorded history to hit the city this winter, and the streets are going to begin looking like canyons if this week's snowstorm adds a significant amount of snow to the incredible 28.5" that fell during "Snowmageddon" last Friday and Saturday. Philadelphia has had two snowstorms exceeding 23" this winter. According to the National Climatic Data Center, the return period for a 22+ inch snow storm is once every 100 years -- and we've had two 100-year snow storms in Philadelphia this winter. It is true that if the winter pattern of jet stream location, sea surface temperatures, etc., are suitable for a 100-year storm to form, this will increase the chances of a second such storm occurring that same year, and thus the odds of having two 100-year storms the same year are not 1 in 10,000. Still, the two huge snowstorms this winter in the Mid-Atlantic are definitely a very rare event one should see only once every few hundred years and is something that has not occurred since modern records began in 1870. The situation is similar for Baltimore and Washington, DC. According to the National Climatic Data Center, the expected return period in the Washington, DC/Baltimore region for snowstorms with more than 16 inches of snow is about once every 25 years. This one-two punch of two major Nor'easters in one winter with 16+ inches of snow is unprecedented in the historical record for the region, which goes back to the late 1800s.


Figure 1. Cars buried in Philadelphia by "Snowmageddon." Image credit: wunderphotographer TragicHipster.

Top 9 snowstorms on record for Philadelphia:

1. 30.7", Jan 7-8, 1996
2. 28.5", Feb 5-6, 2010 (Snowmageddon)
3. 23.2", Dec 19-20, 2009 (Snowpocalypse)
4. 21.3", Feb 11-12, 1983
5. 21.0", Dec 25-26, 1909
6. 19.4", Apr 3-4, 1915
7. 18.9", Feb 12-14, 1899
8. 16.7", Jan 22-24, 1935
9. 15.1", Feb 28-Mar 1, 1941

The top 10 snowstorms on record for Baltimore:

1. 28.2", Feb 15-18, 2003
2. 26.5", Jan 27-29, 1922
3. 24.8", Feb 5-6, 2010 (Snowmageddon)
4. 22.8", Feb 11-12, 1983
5. 22.5", Jan 7-8, 1996
6. 22.0", Mar 29-30, 1942
7. 21.4", Feb 11-14, 1899
8. 21.0", Dec 19-20, 2009 (Snowpocalypse)
9. 20.0", Feb 18-19, 1979
10. 16.0", Mar 15-18, 1892

The top 10 snowstorms on record for Washington, DC:

1. 28.0", Jan 27-28, 1922
2. 20.5", Feb 11-13, 1899
3. 18.7", Feb 18-19, 1979
4. 17.8" Feb 5-6, 2010 (Snowmageddon)
5. 17.1", Jan 6-8, 1996
6. 16.7", Feb 15-18, 2003
7. 16.6", Feb 11-12, 1983
8. 16.4", Dec 19-20, 2009 (Snowpocalypse)
9. 14.4", Feb 15-16, 1958
10. 14.4", Feb 7, 1936

Heavy snow events--a contradiction to global warming theory?
Global warming skeptics regularly have a field day whenever a record snow storm pounds the U.S., claiming that such events are inconsistent with a globe that is warming. If the globe is warming, there should, on average, be fewer days when it snows, and thus fewer snow storms. However, it is possible that if climate change is simultaneously causing an increase in the ratio of "snowstorms with very heavy snow" to "storms with ordinary amounts of snow", we could actually see an increase in very heavy snowstorms in some portions of the world. There is evidence that this is happening for winter storms in the Northeast U.S. -- the mighty Nor'easters like the "Snowmageddon" storm of February 5-6, 2010, and "Snowpocalypse" of December 19, 2009. Let's take a look at the evidence. There are two requirements for a record snow storm:

(1) A near-record amount of moisture in the air (or a very slow moving storm).
(2) Temperatures cold enough for snow.

It's not hard at all to get temperatures cold enough for snow in a world experiencing global warming. 


According to the 2007 Intergovernmental Panel on Climate Change (IPCC) report, the globe warmed 0.74 °C (1.3 °F) over the past 100 years. There will still be colder than average winters in a world that is experiencing warming, with plenty of opportunities for snow. The more difficult ingredient for producing a record snowstorm is the requirement of near-record levels of moisture. Global warming theory predicts that global precipitation will increase, and that heavy precipitation events -- the ones most likely to cause flash flooding -- will also increase. This occurs because as the climate warms, evaporation of moisture from the oceans increases, resulting in more water vapor in the air. According to the 2007 Intergovernmental Panel on Climate Change (IPCC) report, water vapor in the global atmosphere has increased by about 5% over the 20th century and 4% since 1970. This extra moisture in the air will tend to produce heavier snowstorms, assuming it is cold enough to snow. Groisman et al. (2004) found a 14% increase in heavy (top 5%) and 20% increase in very heavy (top 1%) precipitation events in the U.S. over the past 100 years, though mainly in spring and summer. However, the authors did find a significant increase in winter heavy precipitation events have occurred in the Northeast U.S. This was echoed by Changnon et al. (2006), who found, "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."

The strongest cold-season storms are likely to become stronger and more frequent for the U.S.
The U.S. Global Change Research Program (USGCRP) began as a presidential initiative in 1989 and was mandated by Congress in the Global Change Research Act of 1990 (P.L. 101-606), which called for "a comprehensive and integrated United States research program which will assist the Nation and the world to understand, assess, predict, and respond to human-induced and natural processes of global change." This program has put out some excellent peer-reviewed science on climate change that, in my view, is as authoritative as the U.N.-sponsored Intergovernmental Panel on Climate Change (IPCC) reports. In 2009, the USGCRP put out its excellent U.S. Climate Impacts Report, summarizing the observed and forecast impacts of climate change on the U.S. The report's main conclusion about cold season storms was "Cold-season storm tracks are shifting northward and the strongest storms are likely to become stronger and more frequent."

The report's more detailed analysis: "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 (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 (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."
The study also noted that we should expect an increase in lake-effect snowstorms over the next few decades. Lake-effect snow is produced by the strong flow of cold air across large areas of relatively warmer ice-free water. The report says, "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% per decade from 1973 through 2008, amounting to a roughly 30% decrease in ice coverage. 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. In the longer term, lake-effect snows are likely to decrease as temperatures continue to rise, with the precipitation then falling as rain."

Commentary
Of course, both climate change contrarians and climate change scientists agree that no single weather event can be blamed on climate change. However, one can "load the dice" in favor of events that used to be rare -- or unheard of -- if the climate is changing to a new state. It is quite possible that the dice have been loaded in favor of more intense Nor'easters for the U.S. Mid-Atlantic and Northeast, thanks to the higher levels of moisture present in the air due to warmer global temperatures. It's worth mentioning that heavy snow storms should be getting increasingly rare for the extreme southern portion of the U.S. in coming decades. There's almost always high amounts of moisture available for a potential heavy snow in the South -- just not enough cold air. With freezing temperatures expected to decrease and the jet stream and associated storm track expected to move northward, the extreme southern portion of the U.S. should see a reduction in both heavy and ordinary snow storms in the coming decades.

The CapitalClimate blog has a nice perspective on "Snowmageddon," and Joe Romm of climateprogress.org has some interesting things to say about snowstorms in a warming climate.

References
Changnon, S. A., D. Changnon, and T. R. Karl. 2006. Temporal and spatial characteristics of snowstorms in the contiguous United States, J. Appl. Meteor. Climatol., 45, 1141-1155.

Groisman, P. Y., R. W. Knight, T. R. Karl, D. R. Easterling, B. Sun, and J. H. Lawrimore. 2004. Contemporary changes of the hydrological cycle over the contiguous United States: Trends derived from in situ observations, J. Hydrometeor., 5, 64-85.

Kunkel, K. E., P. D. Bromirski, H. E. Brooks, T. Cavazos, A. V. Douglas, D. R. Easterling, K. A. Emanuel, P. Ya. Groisman, G. J. Holland, T. R. Knutson, J. P. Kossin, P. D. Komar, D. H. Levinson, and R. L. Smith. 2008. Observed changes in weather and climate extremes. In Weather and Climate Extremes in a Changing Climate: Regions of Focus: North America, Hawaii, Caribbean, and U.S. Pacific Islands [T. R. Karl, G.A. Meehl, C.D. Miller, S.J. Hassol, A.M. Waple and W.L. Murray (eds.)]. Synthesis and Assessment Product 3.3. U.S. Climate Change Science Program, Washington, DC, pp. 35-80.


Link:  http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=1427