Dr. Jeff Masters' WunderBlog

The future of intense winter storms

Posted by: Dr. Jeff Masters, 02:43 PM GMT am 03. März 2010

When Winter Storm Xynthia powered ashore over Europe last weekend, it brought hurricane-force wind gusts, flooding rains, and a 1-meter storm surge topped by 8-meter high battering waves that overwhelmed sea walls in France, killing scores of people. Today, AIR Worldwide estimated the insured damage from the storm at $1.5 - $3 billion. Intense extratropical cyclones like Xynthia, with central pressures below 970 mb, make up less than 20% of all wintertime cyclones in the Northern Hemisphere, but cause the vast majority of the devastation and loss of life. The ten deadliest winter storms to hit Europe over the past 60 years all had minimum pressures lower than 970 mb. The situation is similar for North America, though the storms generally do not get as intense as their European counterparts (the four major Nor'easters this winter have had central pressures of 968, 969, 978, and 972 mb). It is important, then, to ask if these strongest of the strong storms are changing in frequency, and whether a future warmer world will have more or less of these storms.

Figure 1. Winter Storm Xynthia, as captured by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Aqua satellite. Image was acquired in two separate overpasses on February 27, 2010. MODIS captured the eastern half of the image around 10:50 UTC, and the western half about 12:30 UTC. Forming a giant comma shape, clouds stretch from the Atlantic Ocean to northern Italy. Xynthia peaked in intensity at 18 UTC February 27, with a central pressure of 966 mb. Image credit: NASA.

Have intense Northern Hemisphere winter storms increased in number?
Most of the material for this post comes from three sources: the 2007 IPCC report, a 2009 review titled, Extra-tropical cyclones in the present and future climate: a review, and Weather and Climate Extremes in a Changing Climate, a 2009 report from the U.S. Global Change Research Program (USGCRP). An increasing number of intense winter storms in some regions of the Northern Hemisphere over the last few decades of the 20th century was a common theme of many of the studies reviewed. However, the studies used different measures as to what constitutes an "intense" storm, and have some disagreement on which areas of the globe are seeing more intense storms. A 1996 study by Canadian researcher Steven Lambert (Figure 3) found a marked increase in intense wintertime cyclones (central pressure less than 970 mb) in the latter part of the 20th century. Most of this increase occurred in the Pacific Ocean. Other studies (Geng and Sugi, 2001, and Paciorek et al., 2002) found an increase in intense winter storms over both the North Atlantic and North Pacific in the latter part of the 20th century. Benestad and Chen(2006) found an increase in the number of intense storms over the Nordic countries over the period 1955-1994, but no trend in the western parts of the North Atlantic. Gulev et al. (2001) found a small increase in the number of intense North Pacific storms (core pressure below 980 mb), a large increase in the Arctic, but a small decrease in the Atlantic. McCabe et al. 2001 found an increase at both mid-latitudes and high latitudes, particularly in the Arctic. Hirsch et al. (2001) found that the number of intense Nor'easters along the U.S. East Coast (storms with winds > 52 mph) stayed roughly constant at three storms per year over the period 1951 - 1997. Over the period 1900 to 1990, the number of strong cyclones (less than 992 mb) in November and December more than doubled over the Great Lakes of North America (Angel and Isard, 1998). With regards to Europe, Lionello et al. conclude, "the bulk of evidence from recent studies mostly supports, or at least does not contradict, the finding of an attenuation of cyclones over the Mediterranean and an intensification over Northern Europe during the second part of the twentieth century".

Figure 2. Trends in strong extratropical cyclones with central pressures less than 980 mb, for the period 1989 - 2009, as estimated using thirteen different methods, M02 - M22, defined in Neu et al., 2012. The error-bars represent the 95% confidence range of the trend estimate. A trend is significant at 5% level if the error-bar does not include zero. Four of the thirteen methods showed a slightly significant downward trend in both summertime and wintertime Northern Hemisphere strong extratropical cyclones during the period. None of the methods showed a statistically significant trend in Southern Hemisphere strong extratropical cyclones during either summer or winter. Image credit: U. Neu, M.G. Akperov, N. Bellenbaum, R. Benestad, R. Blender, R. Caballero, A. Cocozza, H.F. Dacre, Y. Feng, K. Fraedrich, J. Grieger, S. Gulev, J. Hanley, T. Hewson, M. Inatsu, K. Keay, S.F. Kew, I. Kindem, G.C. Leckebusch, M.L.R. Liberato, P. Lionello, I.I. Mokhov, J.G. Pinto, C.C. Raible, M. Reale, I. Rudeva, M. Schuster, I. Simmonds, M. Sinclair, M. Sprenger, N.D. Tilinina, I.F. Trigo, S. Ulbrich, U. Ulbrich, X.L. Wang, and H. Wernli, "IMILAST – a community effort to intercompare extratropical cyclone detection and tracking algorithms: assessing method-related uncertainties", Bulletin of the American Meteorological Society, pp. 120919072158001, 2012. http://dx.doi.org/10.1175/BAMS-D-11-00154.1

In summary, the best science we have shows that there has not been a statistically significant increase in the number of intense wintertime extratropical storms globally in the past two decades, but there has been and increase in the North Pacific and Arctic. Increased wave heights have been observed along the coasts of Oregon and Washington during this period, adding confidence to the finding of increased intense storm activity. The evidence for an observed increase in intense wintertime cyclones in the North Atlantic is uncertain. In particular, intense Nor'easters affecting the Northeast U.S. showed no increase in number over the latter part of the 20th century. This analysis is supported by the fact that wintertime wave heights recorded since the mid-1970s by the three buoys along the central U.S. Atlantic coast have shown little change (Komar and Allan, 2007a,b, 2008). However, even though Nor'easters have not been getting stronger, they have been dropping more precipitation, in the form of both rain and snow. Wintertime top 5% heavy precipitation events (both rain and snow) have increased over the Northeast U.S. in recent decades (Groisman et al., 2004), so Nor'easters have been more of a threat to cause flooding problems and heavy snow events. In all portions of the globe, tracks of extratropical storms have shifted poleward in recent decades, in accordance with global warming theory. Note that the historical data base for strong winter storms is in better shape than the data base we are using to try to detect long-term changes in hurricanes. The Ulbrich et al. (2009) review article states:

The IPCC AR4 (cf. Trenberth et al. 2007, p. 312) states that the detection of long-term changes in cyclone measures is hampered by incomplete and changing observing systems. Recent studies found, however, a general reliability of results for cyclones in the Northern Hemisphere. There are no sudden shifts in intensities that would indicate inhomogeneities, and also a comparison with cyclone activity estimated from regional surface and radiosonde data (Wang et al. 2006b; Harnik and Chang 2003) confirmed the general reliability of the data".

However, the data is not as good in the Southern Hemisphere, so the finding that intense winter storms are also increasing in that hemisphere must be viewed with caution.

Figure 3. Number of intense winter cyclones with central pressure less than 970 mb in the Northern Hemisphere, North Pacific, and North Atlantic between 1899 - 1991. Image credit: Lambert, S.J., 1996: Intense extratropical Northern Hemisphere winter cyclone events: 1899-1991. J. Geophys. Res., 101D, 2131921325.

Intense winter storms are expected to increase in number
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. For completeness' sake, some of the studies that show more intense winter cyclones in a warmer world are Lambert (1995), Boer et al. (1992), Dai et al. (2001), Geng and Sugi (2003), Fyfe (2003), Lambert (2004), Leckebusch and Ulbrich (2004), Lambert and Fyfe (2006), Pinto et al. (2007), and Lionello et al. (2008). A review article be Ulbrich et al. provides a nice summary. However, two studies--Pinto et al. (2007) and Bengtsson et al. 2006--suggest that the more intense winter cyclones will affect only certain preferred regions, namely northwestern Europe and Alaska's Aleutian Islands. At least three other studies also find that northwestern Europe--including the British Isles, the Netherlands, northern France, northern Germany, Denmark and Norway--can expect a significant increase in intense wintertime cyclones in a future warmer world (Lionello et al., 2008; Leckebusch and Ulbrich 2004; and Leckebusch et al., 2006). None of these studies showed a significant increase in the number of intense Nor'easters affecting the Northeast U.S. One interesting new study (O'Gorman, 2010) found that wintertime extratropical cyclones in the northern hemisphere would increase in intensity by 2100 primarily because the surface would heat up more than the upper air, making the atmosphere more unstable. In summer, the models predict a decrease in extratropical cyclones in the Northern Hemisphere. In the Southern Hemisphere, these storms were predicted in increase in intensity year-round. The models studied were the 2007 IPCC suite of climate models.

What the IPCC models say
The Lambert and Fyfe (2006) study, titled, "Changes in winter cyclone frequencies and strengths simulated in enhanced greenhouse warming experiments: results from the models participating in the IPCC diagnostic exercise", looked at thirteen models used to formulate the 2007 IPCC Climate Change report. Of these models, eleven simulated an increase in the number and intensity of the most intense cyclones (<970 mb pressure) in the climate expected by 2100. Two of the models did not, so it is fair to say that there is some uncertainty in these results. Nevertheless, the model results are compelling enough that the U.S. Global Change Research Program (USGCRP), a scientific advisory board created by the President and Congress, concluded this in their 2009 U.S. Climate Impacts Report: "Cold-season storm tracks are shifting northward and the strongest storms are likely to become stronger and more frequent". The USGRP concluded that an increase of between four and twelve intense wintertime extratropical storms per year could be expected over the Northern Hemisphere by 2100, depending upon the amount of greenhouse gases put into the air (Figure 3). If we assume that the current climate is producing the same number of intense winter storms as it did over the period 1961-2000--about 53--this represents an increase of between 8% and 23% in intense wintertime extratropical storms.

Figure 4. The projected change in intense wintertime extratropical storms with central pressures < 970 mb for the Northern Hemisphere under various emission scenarios. Storms counted occur poleward of 30°N during the 120-day season beginning November 15. A future with relatively low emissions of greenhouse gases (B1 scenario, blue line) is expected to result in an additional four intense extratropical storms per year, while up to twelve additional intense storms per year can be expected in a future with high emissions (red and black lines). Humanity is currently on a high emissions track. Figure was adapted from Lambert and Fyfe (2006), and was taken from Weather and Climate Extremes in a Changing Climate, a 2009 report from the the U.S. Global Change Research Program (USGCRP). The USGRP began as a presidential initiative in 1989 and was mandated by Congress in the Global Change Research Act of 1990, 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".

Conclusion
The best science we have suggests that there has not been an increase in intense wintertime extratropical cyclones globally in recent decades, though there has been an increase in the Pacific and Arctic. Intense winter extratropical cyclones are expected to in increase in number and shift northwards in a warming climate, with northwest Europe at significantly higher risk of seeing an increase in intense storms. Research by Barredo (2010) suggests that Europe has not yet seen a significant increase in damaging winter storms, since normalized damages from severe winter storms did not increase between 1970 - 2008.

References
Auer, A.H. Jr. and J.M. White, 1982: The Combined Role of Kinematics, Thermodynamics, and Cloud Physics Associated with Heavy Snowfall Episodes. J. Meteor. Soc. Japan, 60, pp 500-507.

Barredo, J.I., 2010, "No upward trend in normalised windstorm losses in Europe: 1970–2008," Nat. Hazards Earth Syst. Sci., 10, 97-104, 2010, doi:10.5194/nhess-10-97-2010

Bengtsson L, Hodges KI, Roeckner E (2006): Storm tracks and climate change. J Clim 19:35183543

Boer GJ, McFarlane NA, Lazare M (1992) Greenhouse gas-induced climate change simulated with the CCC second generation general circulation model. J Climate 5:10451077

Dai, A., et al., 2001b: Climates of the twentieth and twenty-first centuries simulated by the NCAR Climate System Model. J. Clim., 14, 485519.

Fyfe, J.C., 2003: Extratropical southern hemisphere cyclones: Harbingers of climate change? J. Clim., 16, 28022805.

Geng, Q.Z., and M. Sugi, 2003: Possible change of extratropical cyclone activity due to enhanced greenhouse gases and sulfate aerosols - Study with a high-resolution AGCM. J. Clim., 16, 22622274.

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.

Komar, P.D. and J.C. Allan, 2007a: Higher waves along U.S. east coast linked to hurricanes. EOS, Transactions, American Geophysical Union, 88, 301.

Komar, P.D. and J.C. Allan, 2007b: A note on the depiction and analysis of wave-height histograms. Shore & Beach, 75(4), 1- 5.

Komar, P.D. and J.C. Allan, 2008: Increasing hurricane-generated wave heights along the U.S. East coast and their climate controls. Journal of Coastal Research, 24(2), 479-488.

Lambert, S.J., 1995: The effect of enhanced greenhouse warming on winter cyclone frequencies and strengths, J Climate 8:1447-1452

Lambert, S.J., 1996: Intense extratropical Northern Hemisphere winter cyclone events: 1899-1991. J. Geophys. Res., 101D, 2131921325.

Lambert S.J., 2004: Changes in winter cyclone frequencies and strengths in transient enhanced greenhouse warming simulations using two coupled climate models. Atmos Ocean 42:173 181

Lambert, S.J., and J.C. Fyfe, 2006: Changes in winter cyclone frequencies and strengths simulated in enhanced greenhouse warming experiments: results from the models participating in the IPCC diagnostic exercise. Clim. Dyn., 26, 713728.

Leckebusch, G.C., and U. Ulbrich, 2004: On the relationship between cyclones and extreme windstorm events over Europe under climate change. Global Planet. Change, 44, 181193.

Lionello P, Boldrin U, Giorgi F (2008) Future changes in cyclone climatology over Europe as inferred from a regional climate simulation. Clim Dyn 30:657671

Neu, U., M.G. Akperov, N. Bellenbaum, R. Benestad, R. Blender, R. Caballero, A. Cocozza, H.F. Dacre, Y. Feng, K. Fraedrich, J. Grieger, S. Gulev, J. Hanley, T. Hewson, M. Inatsu, K. Keay, S.F. Kew, I. Kindem, G.C. Leckebusch, M.L.R. Liberato, P. Lionello, I.I. Mokhov, J.G. Pinto, C.C. Raible, M. Reale, I. Rudeva, M. Schuster, I. Simmonds, M. Sinclair, M. Sprenger, N.D. Tilinina, I.F. Trigo, S. Ulbrich, U. Ulbrich, X.L. Wang, and H. Wernli, "IMILAST – a community effort to intercompare extratropical cyclone detection and tracking algorithms: assessing method-related uncertainties", Bulletin of the American Meteorological Society, pp. 120919072158001, 2012. http://dx.doi.org/10.1175/BAMS-D-11-00154.1

O'Gorman, P.A., 2010, Understanding the varied response of the extratropical storm tracks to climate change, Proceedings of the National Academy of Sciences, 2010; DOI: 10.1073/pnas.1011547107

Pinto JG, Ulbrich U, Leckebusch GC, Spangehl T, Reyers M, Zacharias S (2007c) Changes in storm track and cyclone activity in three SRES ensemble experiments with the ECHAM5/MPIOM1 GCM. Clim Dyn 29:195210

Ulbrich, U., Leckebusch, G.C. and J.G. Pinto (2009), Extra-tropical cyclones in the present and future climate: a review, Theoretical and Applied Climatology, Volume 96, Numbers 1-2 / April, 2009 DOI 10.1007/s00704-008-0083-8

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1. AwakeInMaryland 02:53 PM GMT am 03. März 2010
Accidently First? Maybe? Thank you Dr. Masters. Forewarned is Forearmed. Member Since: August 19, 2008 Posts: 32 Comments: 1918

4. atmoaggie 03:23 PM GMT am 03. März 2010
So if I think the entire blog post is absurd given that we had far fewer measurements of waves, central pressure, and precip at the beginning of the base period and that the GCMs haven't shown that they can actually figure out the feedbacks to correctly produce a warming result (important to winter storms, certainly) for some CO2 change given, I suppose I'll not be commenting. Parting thought, just because a model correctly produces an observed result in one scenario, that doesn't mean that the model produced that result for the right reasons and should be trusted for all scenarios. I might read the post on Friday. atmo institutes a 48 hour ban for WU's ad dollars from his hits Member Since: August 16, 2007 Posts: 6 Comments: 12461

5. CaribBoy 03:26 PM GMT am 03. März 2010
Link Is that the true SSTs over the Atlantic? 29deg C in the Caribbean is very warm for early march!! Member Since: Oktober 6, 2007 Posts: 0 Comments: 2856

6. PrairieWitch 03:26 PM GMT am 03. März 2010
Thank you Dr. Masters! I appreciate the time and energy you put into each of your blogs.

7. tornadofan 03:32 PM GMT am 03. März 2010
With all the bad science coming out in the press, how can one trust anything coming out of IPCC? Member Since: April 5, 2007 Posts: 83 Comments: 12345

8. weathermanwannabe 03:36 PM GMT am 03. März 2010
Thanks Dr. M; very sombering conclusion if the premise of actual GW holds true and interesting in terms of the general genesis/formation areas of these European winter storms......Summer storms/canes coming off the African coast towards the Caribbean/US and winter storms coming from the same general area towards Europe.........Someone needs to write a paper on any potential correlations as this pattern unfolds. Member Since: August 8, 2006 Posts: 0 Comments: 6703

9. jeffs713 03:38 PM GMT am 03. März 2010
The conclusion makes sense from a semi-layman's standpoint, but as Atmo pointed out... the basis of the conclusion has a lot of holes. I am definitely not one of the GW/CC skeptics, and I am rather skeptical of the methodology of this research, along with the very shaky historical research base. Member Since: August 3, 2008 Posts: 15 Comments: 5722

10. Skyepony (Mod) 03:40 PM GMT am 03. März 2010
Jeff~ Thanks for digging through all the research! Torn~ notice the 18 references..many have nothing to do with the IPCC.. Atmo~ Your not a WU member? Member Since: August 10, 2005 Posts: 144 Comments: 29376

11. Dr. Jeff Masters, Director of Meteorology (Admin) 03:48 PM GMT am 03. März 2010
Quoting jeffs713: The conclusion makes sense from a semi-layman's standpoint, but as Atmo pointed out... the basis of the conclusion has a lot of holes. I am definitely not one of the GW/CC skeptics, and I am rather skeptical of the methodology of this research, along with the very shaky historical research base. The historical data base for strong winter storms is in better shape than what we are using to try to detect long-term changes in hurricanes. The Ulbrich et al. (2009) review article states: The IPCC AR4 (cf. Trenberth et al. 2007, p. 312) states that the detection of long-term changes in cyclone measures is hampered by incomplete and changing observing systems. Recent studies found, however, a general reliability of results for cyclones on the NH: There are no sudden shifts in intensities that would indicate inhomogeneities, and also a comparison with cyclone activity estimated from regional surface and radiosonde data (Wang et al. 2006b; Harnik and Chang 2003) confirmed the general reliability of the data". Jeff Masters

12. KEEPEROFTHEGATE (Mod) 03:52 PM GMT am 03. März 2010
thanks for update doc like i always say what ya see is what ya get Member Since: Juli 15, 2006 Posts: 144 Comments: 40670

13. Chucktown 03:54 PM GMT am 03. März 2010
Quoting atmoaggie: So if I think the entire blog post is absurd given that we had far fewer measurements of waves, central pressure, and precip at the beginning of the base period and that the GCMs haven't shown that they can actually figure out the feedbacks to correctly produce a warming result (important to winter storms, certainly) for some CO2 change given, I suppose I'll not be commenting. Parting thought, just because a model correctly produces an observed result in one scenario, that doesn't mean that the model produced that result for the right reasons and should be trusted for all scenarios. I might read the post on Friday. atmo institutes a 48 hour ban for WU's ad dollars from his hits I agree Atmo - information gathered back then is no way as precise as today's data. And once again, as is the case with 99% Climate Change arguments, we're basing info on the last 100 years or so. This is a speck of time. Until I see absolute proof of a world that is warming due to mankind, I will continue living my life as if the argument of climate change never existed. Member Since: August 27, 2006 Posts: 0 Comments: 1392

14. Skyepony (Mod) 03:54 PM GMT am 03. März 2010
I think the records over the last 100 years aren't too shabby measuring storm pressures on land. This doesn't seem the same as comparing how many storms & their strengths at sea in the early 1900s & now where we'd be comparing satellite info to old ship records. Member Since: August 10, 2005 Posts: 144 Comments: 29376

15. RitaEvac 03:55 PM GMT am 03. März 2010
As long as population growth increases of course storms are going to seem more frequent. It means more frickin people to witness the events Member Since: Juli 14, 2008 Posts: 1 Comments: 8912

16. RitaEvac 03:58 PM GMT am 03. März 2010
Do a population count on the chart above and figure out how many more people have increased.... Member Since: Juli 14, 2008 Posts: 1 Comments: 8912

17. trumpman84 04:00 PM GMT am 03. März 2010
This sounds like the standard AGW argument that "something is going up -- therefore, it must continue to go up indefinetly in the future." The data and graphs are highly suspect as well. For instance, how accurate can data on winter storms really be before the satellite era? Sure, the ones where the center makes landfall in semi-populous areas probably have good readings and records, but what the many who's center (and therefore lowest pressure reading) made landfall over an isolated area where no measurements were taken? Or how about the ones that never make landfall? You also say there has been a remarkable increase in arctic winter storms. How many weather stations were there in the arctic circle in 1915 I wonder? I would presume not very many, and without satellite to detect the presence of storms in the arctic, I seriously doubt if this data can be a true representation. There are other problems with the argument, such as that Pacific wave heigths somehow confirm that their measurements of an increase in winter storms is accurate. I mean, is there really nothing else that could be attributable to Pacific wave height than "intense" winter storms? Anyway, I'm not sure the data presented supports the conclusion in this case. I may not be a meteorologist, climatologist, or even a scientist, but I do consider myself a logical person, and there seems to be more than a few leaps of faiths and instances of wishful thinking in this article. Member Since: Dezember 11, 2009 Posts: 0 Comments: 20

18. Skyepony (Mod) 04:03 PM GMT am 03. März 2010
Rita~ Xanthia took down a sea wall that was build during Napoleon's rule. This isn't the same as counting tornadoes. Member Since: August 10, 2005 Posts: 144 Comments: 29376

19. Chucktown 04:04 PM GMT am 03. März 2010
Quoting RitaEvac: As long as population growth increases of course storms are going to seem more frequent. It means more frickin people to witness the events Also media coverage of any strong storm is tenfold compared to 30 years ago, so sensationalism becomes an issue as well. A blizzard over the northeast in 1923 was only a big deal to those in the northeast. Folks in California probably didn't even know it had occurred. How strong was that nor'easter in January, 1743? Was it 971 mb or 992 mb? I don't know, no records. Member Since: August 27, 2006 Posts: 0 Comments: 1392

20. RitaEvac 04:08 PM GMT am 03. März 2010
Quoting Skyepony: Rita~ Xanthia took down a sea wall that was build during Napoleon's rule. This isn't the same as counting tornadoes. Well after a few hundred years you'd think it would happen at some point. Haven't you watched "Life after people" on Discovery. Nothing lasts forever. That's whats wrong with people, they think everthing is set and stone and never going to change, a perfect little world where we have control and nothing bad can happen. Member Since: Juli 14, 2008 Posts: 1 Comments: 8912

21. Floodman 04:13 PM GMT am 03. März 2010
Quoting RitaEvac: As long as population growth increases of course storms are going to seem more frequent. It means more frickin people to witness the events Uh, we're talking, in large part, Europe here...been settled for thousands of years and has been pretty well FULLY populated for the last 500 years or so...there have, to all intents and purposes, been people to witness the weather events...next argument! Member Since: August 2, 2006 Posts: 10 Comments: 9919

22. hcubed 04:13 PM GMT am 03. März 2010
So, the summary of the post is: 1. ...the studies used different measures as to what constitutes an "intense" storm, and have some disagreement on which areas of the globe are seeing more intense storms... They also couldn't agree on which time period to cover. 2. ...In all portions of the globe, tracks of extratropical storms have shifted poleward in recent decades, in accordance with global warming theory... So where are the studies about the Southern hemisphere? Did we see increased extratropical winter storms there, too? 3. ...thirteen models used to formulate the 2007 IPCC Climate Change report. Of these models, eleven simulated an increase in the number and intensity of the most intense cyclones (<970 mb pressure) in the climate expected by 2100. Two of the models did not... As the doctor said, there is still some uncertainty here. And one last part: 4. ...However, even though Nor'easters have not been getting stronger, they have been dropping more precipitation, in the form of both rain and snow. Wintertime top 5% heavy precipitation events (both rain and snow) have increased over the Northeast U.S. in recent decades... Increased cloud cover, increased snow cover. Both of which will have an effect on the planet's albedo. More humidity in the air increases another greenhouse gas, H2O - likely causing a larger percentage increase than CO2. Increased precipitation also "cleanses" the air, washing more pollutants out of the atmosphere. Cleaner air, more sunlight gets through. Now, I'll follow Atmoaggies' lead, and observe. Be back in a couple of days... Member Since: Mai 18, 2007 Posts: 286 Comments: 1639

23. jeffs713 04:22 PM GMT am 03. März 2010
Quoting JeffMasters: The historical data base for strong winter storms is in better shape than what we are using to try to detect long-term changes in hurricanes. The Ulbrich et al. (2009) review article states: The IPCC AR4 (cf. Trenberth et al. 2007, p. 312) states that the detection of long-term changes in cyclone measures is hampered by incomplete and changing observing systems. Recent studies found, however, a general reliability of results for cyclones on the NH: There are no sudden shifts in intensities that would indicate inhomogeneities, and also a comparison with cyclone activity estimated from regional surface and radiosonde data (Wang et al. 2006b; Harnik and Chang 2003) confirmed the general reliability of the data". Jeff Masters True. My concern is more with the North Pacific storms, as that lane was not as heavily traveled as it is now, and ship records may be more spotty than those in the North Atlantic. Also, by relying on ship reports, strong storms can be completely missed at their peak strength. While we do have corrolary evidence of strong storms in the North Pacific based on wave heights along the NW coast, we don't have as much direct evidence as we do with North Atlantic storms. While I agree with the overall findings, (more moisture = stronger storms, and less temp variation between tropics and poles = less storms overall) the foundation of the research is easy to criticize based on the methodology used. Then again... some research will be critized regardless of the foundation. That said, thank you for replying to my post! Member Since: August 3, 2008 Posts: 15 Comments: 5722

24. Skyepony (Mod) 04:22 PM GMT am 03. März 2010
Arctic circle is & has been populated by people with barometers for more than 100 years.. I think it was Aristotle that used logic to reason if you add sewage to garbage rats are created.. Yes age did have something to do with the undermining of the sea wall. It was reported to be in need of repair. My point was..the sea wall was so old because it has been protecting a decent population more than one hundred years. Wonder why they want to rebuild it higher? Member Since: August 10, 2005 Posts: 144 Comments: 29376

25. Dr. Jeff Masters, Director of Meteorology (Admin) 04:32 PM GMT am 03. März 2010
Quoting hcubed: So where are the studies about the Southern hemisphere? Did we see increased extratropical winter storms there, too? From the Ulbrich et al. (2009) review paper, regarding intense Southern Hemisphere cyclones: "Special note should be given to the findings concerning only cyclones deeper than 980 hPa: a significant increase is found for the entire SH. In addition, Lim and Simmonds (2002) found a statistically significant increase in the number of explosively deepening (at least 1 hPa per hour) systems. More recently, Wang et al. (2006a) identified an increasing trend of strong-cyclone activity over the circumpolar Southern Ocean in winter (JAS) and summer (JFM)". However, data quality and length of record is shorter in the SH, thus I decided not to talk about it. Jeff Masters

26. Ossqss 04:35 PM GMT am 03. März 2010
My question would be -- Does any of this fall outside the range of natural variation? The answer is, we don't really know. Looks like a few painful days ahead for this blog again :( I'm gone >>>>> Member Since: Juni 12, 2005 Posts: 6 Comments: 8154

27. Chicklit 04:46 PM GMT am 03. März 2010
From Dr. Masters' Blog: It is important, then, to ask if these strongest of the strong storms are changing in frequency, and whether a future warmer world will have more or less of these storms. You address the question extremely well, Dr. Masters--no small feat! Member Since: Juli 11, 2006 Posts: 14 Comments: 10255

28. jeffs713 04:46 PM GMT am 03. März 2010
Quoting Ossqss: My question would be -- Does any of this fall outside the range of natural variation? The answer is, we don't really know. Looks like a few painful days ahead for this blog again :( I'm gone >>>>> I feel ya there. Its going to painful on here until the next post. Thankfully, I'm moving tomorrow, so I won't get to "enjoy" the drama. Member Since: August 3, 2008 Posts: 15 Comments: 5722

29. xcool 04:55 PM GMT am 03. März 2010
Link March 3, 2010 First Look: 2010 Atlantic Hurricane Season Outlook Member Since: September 26, 2009 Posts: 2 Comments: 15503

31. Levi32 05:05 PM GMT am 03. März 2010
"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" (emphasis added) Dr. Masters, two questions: 1) How can they know storms will drop more precipitation in a warmer world. Yes there would be more moisture evaporated into the atmosphere, but you have to cool the air back down to condensate that moisture back into a solid or liquid state. If the world is warmer overall, who's to say the balance between how much moisture exists in the atmosphere and how much is allowed to condensate won't stay about the same? A good counterargument I can see to this would be that the atmosphere of a warmer world would indeed be able to hold more water vapor, but dewpoints would rise as well, so I can see people saying that since the temperature needed to condensate the water rises along with the global temperature, then my argument has no merit. However, again, who's to say the balance will change? It's easy to say a higher dewpoint means more condensation, but wouldn't the global temperature rise negate that effect? Because the air would not be allowed to cool as much inside the clouds, and so only a certain amount of moisture would still be squeezed out of the atmosphere, despite higher overall moisture content. If future temperatures inside clouds were allowed to cool as much as now with a higher dewpoint, then yes there would be more condensation, but not necessarily if the temperature rises too. So my question is, can they really calculate what the balance will be between condensation and total moisture in the atmosphere? Can they prove that there will be more precipitation? 2) You mention how latent heat gets released in extratropical storms by condensation, rises, and lowers the storm's central pressure. This can tie in with my above question if there really is a whole lot more condensation, and if there isn't then there wouldn't be more latent heat released. But the other point to be made here is that latent heat lowers the surface pressure of a storm because the heated air rises, inviting more air in at the surface of the storm. In an overall warmer world, who's to say the buoyancy of that heated air will be greater, which is what you would need to say if storms would have lower central pressures. If everything warms, the air warmed by latent heat wouldn't necessarily be warmer relative to all the other "globally warmed" air around it, which means it wouldn't rise as fast, and surface air pressures wouldn't fall as fast or as much. This is the same principle as what you mentioned in your post about the poles and the equator both warming. If it all warms, the balance of difference between equator and poles wouldn't change, and therefore the storm budget wouldn't change. (yes I know you said the poles would warm more than the tropics, making storms needed less, but the logic is still the same). So again my question would be, can they prove this? Is this something they are assuming? Or can they actually show that the balance will be tipped in both of these processes. Member Since: November 24, 2005 Posts: 587 Comments: 25461

32. GetReal 05:09 PM GMT am 03. März 2010
Quoting tornadofan: With all the bad science coming out in the press, how can one trust anything coming out of IPCC? Thank you for pointing that fact out... Member Since: Juli 4, 2005 Posts: 204 Comments: 8196

33. Levi32 05:09 PM GMT am 03. März 2010
Quoting tornadofan: With all the bad science coming out in the press, how can one trust anything coming out of IPCC? Yes indeed how can we?? We still trust them? Member Since: November 24, 2005 Posts: 587 Comments: 25461

34. RitaEvac 05:12 PM GMT am 03. März 2010
Natural Variation, just like natural selection Member Since: Juli 14, 2008 Posts: 1 Comments: 8912

36. jeffs713 05:14 PM GMT am 03. März 2010
Levi, Correct me if I am wrong, but doesn't the amount of possible moisture increase on an exponential scale as temp increases? (or at least, the increase in possible moisture as temp rises is not a linear function) That could explain the moisture increase. Also, while the surface temps may be higher, and more moist, the air temp still drops as one ascends in the clouds. Condensation will happen regardless. Member Since: August 3, 2008 Posts: 15 Comments: 5722

37. nrtiwlnvragn 05:15 PM GMT am 03. März 2010
Quoting Skepticall: A new study predicts that global warming, contrary to claims made by Nobel Laureate Al Gore and the his fellow climate alarmists, will actually reduce the number of hurricanes by as much as 34 percent by the year 2100. The report just published in the journal Nature Geoscience also found that the increase in tropical storm activity the planet has seen since 1995 is part of a natural cycle completely unrelated to increases in atmospheric carbon dioxide. These revelations represent another serious crack in the claims made by the United Nations Intergovernmental Panel on Climate Change, and therefore seem quite unlikely to be reported by American media that have been largely ignoring all the errors that have been found recently in key IPCC documents. http://newsbusters.org/blogs/noel-sheppard/2010/03/01/new-study-says-global-warming-reduces-hurrica ne-active-will-media-not That is not true. The actual finding from Tropical cyclones and climate change: It remains uncertain whether past changes in any tropical cyclone activity (frequency, intensity, rainfall, and so on) exceed the variability expected through natural causes, after accounting for changes over time in observing capabilities. Member Since: September 23, 2005 Posts: 11 Comments: 8946

38. Levi32 05:16 PM GMT am 03. März 2010
Quoting jeffs713: Levi, Correct me if I am wrong, but doesn't the amount of possible moisture increase on an exponential scale as temp increases? (or at least, the increase in possible moisture as temp rises is not a linear function) That could explain the moisture increase. Also, while the surface temps may be higher, and more moist, the air temp still drops as one ascends in the clouds. Condensation will happen regardless. This is one reason I am asking because I have not gone to school yet and don't know all the mathematical things involved here. Temperature would still drop as you go up but the entire troposphere is supposed to warm so the air parcel's relative buoyancy wouldn't necessarily change, and the rate of cooling wouldn't be greater if the entire air column warmed. Member Since: November 24, 2005 Posts: 587 Comments: 25461

39. VAbeachhurricanes 05:16 PM GMT am 03. März 2010
Quoting Levi32: "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" (emphasis added) Dr. Masters, two questions: 1) How can they know storms will drop more precipitation in a warmer world. Yes there would be more moisture evaporated into the atmosphere, but you have to cool the air back down to condensate that moisture back into a solid or liquid state. If the world is warmer overall, who's to say the balance between how much moisture exists in the atmosphere and how much is allowed to condensate won't stay about the same? A good counterargument I can see to this would be that the atmosphere of a warmer world would indeed be able to hold more water vapor, but dewpoints would rise as well, so I can see people saying that since the temperature needed to condensate the water rises along with the global temperature, then my argument has no merit. However, again, who's to say the balance will change? It's easy to say a higher dewpoint means more condensation, but wouldn't the global temperature rise negate that effect? Because the air would not be allowed to cool as much inside the clouds, and so only a certain amount of moisture would still be squeezed out of the atmosphere, despite higher overall moisture content. If future temperatures inside clouds were allowed to cool as much as now with a higher dewpoint, then yes there would be more condensation, but not necessarily if the temperature rises too. So my question is, can they really calculate what the balance will be between condensation and total moisture in the atmosphere? Can they prove that there will be more precipitation? 2) You mention how latent heat gets released in extratropical storms by condensation, rises, and lowers the storm's central pressure. This can tie in with my above question if there really is a whole lot more condensation, and if there isn't then there wouldn't be more latent heat released. But the other point to be made here is that latent heat lowers the surface pressure of a storm because the heated air rises, inviting more air in at the surface of the storm. In an overall warmer world, who's to say the buoyancy of that heated air will be greater, which is what you would need to say if storms would have lower central pressures. If everything warms, the air warmed by latent heat wouldn't necessarily be warmer relative to all the other "globally warmed" air around it, which means it wouldn't rise as fast, and surface air pressures wouldn't fall as fast or as much. This is the same principle as what you mentioned in your post about the poles and the equator both warming. If it all warms, the balance of difference between equator and poles wouldn't change, and therefore the storm budget wouldn't change. (yes I know you said the poles would warm more than the tropics, making storms needed less, but the logic is still the same). So again my question would be, can they prove this? Is this something they are assuming? Or can they actually show that the balance will be tipped in both of these processes. damn good post levi, its all fudgy science, no buoys were out in the middle of the Atlantic in 1900 measuring wave heights and pressure readings of storms, plus cant we have a graph that comes closer to the present time period then 20 years? i mean its 2010, why is the graph ending at 1990? does the 1990-2010 data not support their claims so its not included? Member Since: September 6, 2007 Posts: 0 Comments: 4802

40. hcubed 05:17 PM GMT am 03. März 2010
Quoting JeffMasters: From the Ulbrich et al. (2009) review paper, regarding intense Southern Hemisphere cyclones: "Special note should be given to the findings concerning only cyclones deeper than 980 hPa: a significant increase is found for the entire SH. In addition, Lim and Simmonds (2002) found a statistically significant increase in the number of explosively deepening (at least 1 hPa per hour) systems. More recently, Wang et al. (2006a) identified an increasing trend of strong-cyclone activity over the circumpolar Southern Ocean in winter (JAS) and summer (JFM)". However, data quality and length of record is shorter in the SH, thus I decided not to talk about it. Jeff Masters Said I'd stay away, but: So it's possible that the increasing trend of strong-cyclone activity over the circumpolar Southern Ocean can be tied to increased SST, and the fact that the SH has more water, therefore more fuel for the storms? Member Since: Mai 18, 2007 Posts: 286 Comments: 1639

42. jeffs713 05:20 PM GMT am 03. März 2010
35. Let me ask you this... What motivation does the "media" have for misleading the public as you allege? Right now, there is so much misinformation, wrong information, vague information, and disinformation out there that the truth is nigh impossible to discern. Until the noise level drops, and groups with their own agenda stop spewing forth bad information (in an attempt to muddy the waters BOTH ways)... The truth will never come out. Think about it, if someone tells you something that you know is wrong, do you think they will listen to you much if your response is to yell at them and discredit everything they say? Do you think most civilized people will listen to your yelling and misinformation? Member Since: August 3, 2008 Posts: 15 Comments: 5722

43. nrtiwlnvragn 05:20 PM GMT am 03. März 2010
Quoting Skepticall: I love going to sites that the government runs!!! They are just so true and never lie! So you are saying one of the authors of the report, who works for the government, is lieing. Member Since: September 23, 2005 Posts: 11 Comments: 8946

44. jeffs713 05:22 PM GMT am 03. März 2010
Quoting Levi32: This is one reason I am asking because I have not gone to school yet and don't know all the mathematical things involved here. Temperature would still drop as you go up but the entire troposphere is supposed to warm so the air parcel's relative buoyancy wouldn't necessarily change, and the rate of cooling wouldn't be greater if the entire air column warmed. True. If moisture content was an exponential (or geometric) relationship, and not linear, higher temp would be tied to higher moisture levels overall. Anyone who has more knowledge in meteorology have any input? Member Since: August 3, 2008 Posts: 15 Comments: 5722

45. VAbeachhurricanes 05:27 PM GMT am 03. März 2010
For more reading on this, go here. http://docs.google.com/viewer?a=v&q=cache:hAmFhpyDwnwJ:ams.confex.com/ams/pdfpapers/94332.pdf+extra tropical+cyclone+intensity+graphs&hl=en&gl=us&pid=bl&srcid=ADGEESgrT49ukFdmPcyURdsrWewfDBRlQ0uUfYhYn DY8p76l1vDREWmGhO-ujKvR6PUjKfOP7wsisa9s7EhJwPCpssEXJ8t9YPUTQi-UrUYSK1FC60eCJ40hrXHg1cXtWekwTad25MpS& sig=AHIEtbT5GOkOm-BQLSmU0Leul6OQ4mZGSA a very interesting read Member Since: September 6, 2007 Posts: 0 Comments: 4802

47. Levi32 05:30 PM GMT am 03. März 2010
Quoting jeffs713: True. If moisture content was an exponential (or geometric) relationship, and not linear, higher temp would be tied to higher moisture levels overall. Anyone who has more knowledge in meteorology have any input? I never said it wouldn't result in more moisture overall, that is a fundamental truth. I challenged how much condensation would still happen due to the overall warming of the entire atmosphere. Member Since: November 24, 2005 Posts: 587 Comments: 25461

49. MrJoeBlow 05:37 PM GMT am 03. März 2010
I have to say it and I question the motive of anyone who uses the IPCC nowadays. I will follow the leads of those others and not return until Friday.

50. nrtiwlnvragn 05:37 PM GMT am 03. März 2010
Quoting Skepticall: I'm not 100% sure if your being sarcastic but how many times has the government lied to you? I'm not questioning if the government is lieing, you are. I provided you a link to the actual paper on hurricanes and global warming which showed the article you referenced did not accurately reflect what was stated. Your response was to attack the messenger. Member Since: September 23, 2005 Posts: 11 Comments: 8946

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