Heavy snowfall in a warming world
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, that will increase the chances for a second such storm to occur that same year, and thus the odds have 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 D.C. According to the National Climatic Data Center, the expected return period in the Washington D.C./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. Car buried in Virginia by "Snowmageddon" on February 8, 2010. Image credit: wunderphotographer Brabus Cave.
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, D.C.:
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 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 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 percent per decade from 1973 through 2008, amounting to a roughly 30 percent 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".
Figure 2. The annual average number of snowstorms with a 6 inch (15.2 cm) or greater accumulation, from the years 1901 - 2001. A value of 0.1 means an average of one 6+ inch snowstorm every ten years. Image credit: Changnon, S.A., D. Changnon, and T.R. Karl, 2006, Temporal and Spatial Characteristics of Snowstorms in the Contiguous United States, J. Applied Meteorology and Climatology, 45, 8, pp. 1141-1155, DOI: 10.1175/JAM2395.1.
More heavy snowstorms occur in warmer-than-average years
Another interesting result from the Changnon et al. (2006) paper (Figure 2) is the relationship between heavy snowstorms and the average winter temperature. For the contiguous U.S. between 1900 - 2001, the authors found that 61% - 80% of all heavy snowstorms of 6+ inches occurred during winters with above normal temperatures. In other words, the old adage, "it's too cold to snow", has some truth to it. The authors also found that 61% - 85% of all heavy snowstorms of 6+ inches occurred during winters that were wetter than average. The authors conclude, "a future with wetter and warmer winters, which is one outcome expected (National Assessment Synthesis Team 2001), will bring more heavy snowstorms of 6+ inches than in 1901 - 2000. The authors found that over the U.S. as a whole, there had been a slight but significant increase in heavy snowstorms of 6+ inches between 1901 - 2000. However, a separate paper by Houston and Changnon (2009), "Characteristics of the top ten snowstorms at First-Order Stations in the U.S.", found that there was no upward or downward trend in the very heaviest snowstorms for the contiguous U.S. between 1948 - 2001, as evaluated by looking at the top ten snowstorms for 121 major cities.
Commentary
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 nature's weather 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 [Karl, T.R., 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.
Congratulations, New Orleans!
Congratulations to everyone in New Orleans, for the Saints' Super Bowl victory! It's great to the see the city celebrating after enduring so many years of hardship in the wake of Hurricane Katrina.
Jeff Masters
Reader Comments
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The table-setters are there. For instance, how do return periods change after accounting for known climatological factors? We're in a unique climatological setup that historically favors big East Coast snows: positive ENSO (Hirsch et al 2001), and negative NAO (Hartley & Kables 1998).
I think the more interesting and immediate question is 1) how does this season differ from previous analog seasons, and 2) does that provide further evidence towards effects from a warming climate.
References:
Hartley S., and M. J. Keables, 1998: Synoptic associations of winter climate and snowfall variability in New England, USA, 1950– 1992. Int. J. Climatol, 18, 281–298.
Hirsch, M.E., A.T. DeGaetano, and S.J. Colucci, 2001: An East Coast Winter Storm Climatology. J. Climate, 14, 882–899.
It's coming for you.
And Avocados and Almonds, and and and...
Link
The last oranges i had, been very "soft?" - the orange meat? becomes looose with easy.
I'm feeling suicidal...
twins!
;)
:)
Comparing the measurements made in modern times to temperature proxies has matched very well. Same for CO2 concentrations. It's the closest thing we're going to find to a time machine. Pining for "real" measurements isn't going to help. Scientists are continually looking at new proxies to add to the mountain of evidence. It's not just one, it's several cross-correlated proxies that make up the body of evidence.
We have a very good idea of the temperature trend for ancient temperatures, CO2 emissions, and solar input. All the other feedbacks get rolled together with the CO2 feedback as part of that multiplier, over the long term.
On the flip side, at night clouds are very effective at keeping the ground warm. You can predict based on night-time low vs daytime high whether or not it was a cloudy night. I think raising the nighttime low will have a much greater effect, for example if you don't have a clear night water isn't going to be able to freeze over.
Best case, clouds can blunt only part of the rise, or make it worse. They will be unable to completely neutralize it (otherwise the clouds themselves will go away, right?). Will they be able to reduce the increase significantly? I don't find this likely, because then we would never see paleoclimate temperature changes.
Thank you. Good point and good post.
Additionally, I am not aware of any IPCC statement about east coast snowfall, only the Changnon study Dr. M referenced.
What the total US snowfall trend? Ummm, looks very cyclical to me:
I don't think any real, credible effect can seriously be flushed out of this data...yet, maybe someday.
Did you draw a face on that navel .................................................................................................... ....... too?
:)
Very good example.
This doesn't answer the following, IMO:
We have so little data about the feedbacks and how they all work together that we, collectively, have no idea what the temperature, or temperature trend, would be without our CO2 emissions. (Though everyone has a few ideas, no one has good enough data.)
And: "On the flip side, at night clouds are very effective at keeping the ground warm. You can predict based on night-time low vs daytime high whether or not it was a cloudy night. I think raising the nighttime low will have a much greater effect, for example if you don't have a clear night water isn't going to be able to freeze over."
1. Do you know how much of the planet routinely reaches near-100% relative humidity at night? Fully consumed absorption wavelengths cannot be increased.
2. And Freeze over? For most of the year in most inhabitable places (most of the planet) water freezing probably isn't a good example...
Here comes the parrot, SQUAWK!
Hey, why don't you post the age of stupid stupid.
The mouse in your pocket...the Uberdoubter
AS OF 315 PM TUESDAY...MAIN STORY WEDNESDAY/WEDNESDAY EVENING WILL
BE THE STRONG WESTERLY WINDS THAT WILL DEVELOP ACROSS THE ENTIRE
AREA AS THE LOW BOMBS OFF THE MID ATLANTIC COAST. SUSTAINED WINDS
WILL BE 25 TO 35 MPH WITH GUSTS OF 45 TO 50 MPH. ALONG THE OUTER
BANKS THERE IS A POTENTIAL FOR SUSTAINED WINDS OF 40 MPH SO WILL
ISSUE A HIGH WIND WARNING THAT AREA. IN ADDITION TO THE WIND
WARNINGS AND ADVISORIES...THE STRONG WESTERLY WINDS WILL LEAD TO:
1) DANGEROUSLY LOW WATER LEVELS IN THE THE NEUSE AND PAMLICO
RIVERS PROMPTING THE ISSUANCE OF A LOW WATER ADVISORY
you sound like my wife
-- Changed Discussion --AS OF 315 PM TUESDAY...WILL BE WATCHING LOW PRESSURE FORECAST TO
DEVELOP IN THE GULF OF MEXICO AND MOVE OFF THE SE COAST SOUTH OF
THE AREA LATE FRIDAY AND SATURDAY. RIGHT NOW THE CONSENSUS OF THE
MODELS KEEP THE MEASURE ABLE PRECIPITATION WITH THIS SYSTEM SOUTH
OF THE AREA. SINCE TEMPERATURES WILL BE COLD ENOUGH FOR SNOW WE
WILL HAVE TO WATCH THIS EVOLUTION AND TRACK OF THIS SYSTEM
CLOSELY. THE GLOBAL GEM WAS MUCH FURTHER NORTH THAN THE
CONSENSUS...AT OUTLIER OR A SIGNAL OF THINGS TO COME. FOR NOW WILL
BE STICKING WITH A DRY FORECAST ALTHOUGH A FEW FLURRIES WILL BE
POSSIBLE WITH A NORTHERN STREAM SYSTEM LATE SUNDAY AND SUNDAY NIGHT.-- End Changed Discussion --
The Neuse and Pamlico Rivers are tidal rivers as opposed to the inland rivers that have the flood warnings. We have been having the same warnings here in South Carolina, again for the inland rivers not effected by the tide.
where is that for large? you live in VA right?
Wednesday
Snow. Snow accumulation of 4 to 6 inches. Brisk with highs in the lower 30s. Northeast winds 10 to 15 mph...increasing to 15 to 25 mph with gusts up to 35 mph in the afternoon. Chance of snow near 100 percent.
Wednesday Night
Snow. Total snow accumulation of 6 to 10 inches. Blustery. Near steady temperature in the upper 20s. North winds 20 to 25 mph with gusts up to 45 mph. Chance of snow 90 percent.
And even before the first snowflake has begun to fall...
Cambridge Snow Emergency Parking Ban in Effect Wednesday, Feb. 10 at Noon
It'll be interesting to see if the plows can keep up with it, or whether my daughter will get that snow day off from HS she's been wishing for. If so, it'll be the first one this school year, which is unusually late.
Danger Room What’s Next in National Security
With Darpa’s ‘Transparent Earth,’ Underground Doesn’t Mean Out of Sight
The Pentagon’s science fringe has been trying to lord over the natural elements for years now. They’ve talked about planet hacking and screwing with enemy climates, and they still want to harness the power of lightning.
This year, military science has more of an “all-encompassing” goal for global mastery. As part of its budget for the upcoming fiscal year, Pentagon extreme research agency Darpa is launching the “Transparent Earth” project. They’ll invest $4 million into the creation of real-time, 3-D maps that display “the physical, chemical and dynamic properties of the earth down to 5 kilometer depth.”
At first, the idea doesn’t sound all that impressive. The earth is more than 3,500 miles deep, from crust to core, so Darpa’s plan would literally just scratch at the surface. But geologists and geophysicists still know very little about the day-to-day goings-on underground, even at a depth as shallow as 5 km (that’s 3.1 miles). The deepest drilling of the planet was a Soviet hole on the Kola Peninsula, which took 19 years and made it around 7.5 miles into the crust, and even NASA still uses land-based GPS signals to predict volcanic eruptions.
Rather than a mega-drill, Darpa wants to harness innovations in sensor technology to develop a constantly-updating model of planetary activity. They’ll use sensors to detect “natural indicators of subsurface activity,” and then take advantage of mathematical algorithms designed to estimate various natural earthly phenomena, including geophysical turbulence and shifting tectonic plates.
Algorithms are already used in planetary mapping and predictive science, but adding high-tech sensors would provide a constant stream of new data. And that kind of accuracy could have serious planetary implications: Changes in the earth’s crust can explain and predict volcanic eruptions, earthquakes and even the formation of mountain ranges.
After they successfully combine sensors and mathematics, Darpa’s end goal would put even NASA’s satellite footage to shame:
http://www.wired.com/dangerroom/2010/02/darpas-plan-for-world-domination-map-entire-planets-undergr ound/
If we were to get any this season, this would be the right kind of setup. The last few runs of the NAM and GFS has the cold air lagging a little further back than previous runs. It looks like I-95 and west has the best chance around our parts. If we do see any "s---", it would be after midnight Friday into early Saturday. The typical race will be on, how quick does the moisture move out and how fast does the old 540 line move in to promote dendritic crystalization of water.
Amy...I saw it...just trying to behave...a little...
I'm aware of that, but still, even the Neuse was at flood stage in Tarboro(admitedly outside of tidal area I believe). If nothing else, they are still full of a lot of recent rain and to hear they will be extremely low that quickly is impressive of the winds coming our way. Wouldn't be surprised if a lot of trees go down considering how saturated the soil is.
Either way Press, it doesn't look like much. Unless something significantly changes with the models, the majority of the precip we see will be rain. Crazy El Nino winter. Living here now for 11 years and this by far is the coldest and wettest. I haven't teed it up in 3 weeks. We'll just blame it on Walsh !!
You should be rain along the Georgia coast as well - there will definitely be "some" snow in the south - Reading some of the other NWS discos, it seems to be an I-10 storm - still a lot more questions than answers and over 60 hours out so a lot can change
I think I have had enough now....
Taco :0)
you and my wife should chat...she's having some sort of unGodly golf withdrawal...saw Bill Sat nite at mass...but didn't get to speak...
Link
well...maybe snow ain't so bad afterall...
LA CRESCENTA, Calif. (KABC) -- Southern California braces for another nasty storm, and more flooding and mudslides are feared, especially in communities still cleaning up after the destruction over the weekend.
A flash flood warning is in effect for the Station, Morris and Santa Anita burn areas of Los Angeles County until 5 p.m.
Mandatory evacuation orders are in place for people in La Canada Flintridge, Acton, Soledad Canyon, Aliso Canyon and La Crescenta. Residents were asked to leave by 10 a.m., and officials said the evacuations may be lifted by Wednesday night.
:)
That last episode has me LOST. LOL I guess we are dealing with alternate realities or something.
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