Florida shivers; Hot Arctic-Cold Continents pattern is back

By: Dr. Jeff Masters , 5:36 PM GMT on December 14, 2010

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Cold air sweeping southwards behind the fierce snowstorm that roared through the Upper Midwest over the weekend is bringing record low temperatures over much of the Southeast this morning. However, preliminary indications are that Central Florida's orange groves fared better than expected, and there were no reports of widespread damage to the orange crop. Record lows this morning included 32°F at West Palm Beach, 50°F in Key West, and 20°F in Jacksonville. Cold air flowing over the relatively warm waters of Lake Erie and Lake Ontario are creating heavy lake-effect snows, with 5 – 9 inches of new snow expected near Cleveland, OH today, and 2 – 5 inches near Syracuse, NY.

Hot Arctic-Cold Continents
I'm in San Francisco this week for the world's largest gathering of Earth scientists, the annual American Geophysical Union (AGU) conference. Over 15,000 scientists have descended upon the city, and there are a ridiculous number of fascinating talks on every conceivable aspect of Earth science, including, of course, climate change. One talk I attended yesterday was called, "Hot Arctic-Cold Continents: Hemispheric Impacts of Arctic Change.” The talk was given by Dr. Jim Overland of NOAA's Pacific Marine Environmental Laboratory, one of the world's experts on Arctic weather and climate (I spent many long months flying in the Arctic with him during the three Arctic field programs I participated in during the late 1980s.) Dr. Overland discussed the remarkable winter of 2009 – 2010, which brought record snowstorms to Europe and the U.S. East Coast, along with the coldest temperatures in 25 years, but also brought the warmest winter on record to Canada and much of the Arctic. He demonstrated that the Arctic is normally dominated by low pressure in winter, and a “Polar Vortex” of counter-clockwise circulating winds develops surrounding the North Pole. However, during the winter of 2009-2010, high pressure replaced low pressure over the Arctic, and the Polar Vortex weakened and even reversed at times, with a clockwise flow of air replacing the usual counter-clockwise flow of air around the pole. This unusual flow pattern allowed cold air to spill southwards and be replaced by warm air moving poleward. This pattern is kind of like leaving the refrigerator door ajar--the refrigerator warms up, but all of the cold air spills out into the house.


Figure 1. Conceptual diagram of how Arctic sea ice loss affects winter weather, from NOAA's Future of Arctic Sea Ice and Global Impacts web page.

The North Atlantic Oscillation (NAO)
This is all part of a natural climate pattern known as the North Atlantic Oscillation (NAO), which took on its most extreme configuration in 145 years of record keeping during the winter of 2009 – 2010. The NAO is a climate pattern in the North Atlantic Ocean of fluctuations in the difference of sea-level pressure between the Icelandic Low and the Azores High. It is one of oldest known climate oscillations--seafaring Scandinavians described the pattern several centuries ago. Through east-west oscillation motions of the Icelandic Low and the Azores High, the NAO controls the strength and direction of westerly winds and storm tracks across the North Atlantic. A large difference in the pressure between Iceland and the Azores (positive NAO) leads to increased westerly winds and mild and wet winters in Europe. Positive NAO conditions also cause the Icelandic Low to draw a stronger south-westerly flow of air over eastern North America, preventing Arctic air from plunging southward. In contrast, if the difference in sea-level pressure between Iceland and the Azores is small (negative NAO), westerly winds are suppressed, allowing Arctic air to spill southwards into eastern North America more readily. Negative NAO winters tend to bring cold winters to Europe and the U.S. East Coast, but leads to very warm conditions in the Arctic, since all the cold air spilling out of the Arctic gets replaced by warm air flowing poleward.

The winter of 2009 - 2010 had the most extreme negative NAO since record keeping began in 1865. This "Hot Arctic-Cold Continents pattern", resulting in a reversal of Polar Vortex and high pressure replacing low pressure over the Arctic, had occurred previously in only four winters during the past 160 years—1969, 1963, 1936, and 1881. Dr. Overland called the winter of 2009 – 2010 at least as surprising at the record 2007 loss of Arctic sea ice. He suspected that Arctic sea ice loss was a likely culprit for the event, since Francis et al. (2009) found that during 1979 - 2006, years that had unusually low summertime Arctic sea ice had a 10 - 20% reduction in the temperature difference between the Equator and North Pole. This resulted in a weaker jet stream with slower winds that lasted a full six months, through fall and winter. The weaker jet caused a weaker Aleutian Low and Icelandic Low during the winter, resulting in a more negative North Atlantic Oscillation, allowing cold air to spill out of the Arctic and into Europe and the Eastern U.S. Dr. Overland also stressed that natural chaos in the weather/climate system also played a role, as well as the El Niño/La Niña cycle and natural oscillations in stratospheric winds. Not every year that we see extremely high levels of Arctic sea ice loss will have a strongly negative NAO winter. For example, the record Arctic sea ice loss year of 2007 saw only a modest perturbation to the Arctic Vortex and the NAO during the winter of 2007 – 2008.

However, the strongly negative NAO is back again this winter. High pressure has replaced low pressure over the North Pole, and according to NOAA, the NAO index during November 2010 was the second lowest since 1950. This strongly negative NAO has continued into December, and we are on course to have a top-five most extreme December NAO. Cold air is once again spilling southwards into the Eastern U.S. And Europe, bringing record cold and fierce snowstorms. At the same time, warm air is flowing into the Arctic to replace the cold air spilling south--temperatures averaged more than 10°C (18°F) above average over much of Greenland so far this month. The latest 2-week forecast from the GFS model predicts that the Hot Arctic-Cold Continents pattern will continue for the next two weeks. However, the coldest air has sloshed over into Europe and Asia, and North America will see relatively seasonable temperatures the next two weeks.

For more information
The NOAA web page, Future of Arctic Sea Ice and Global Impacts has a nice summary of the “Hot Arctic-Cold Continents” winter pattern.

NOAA's Arctic Report Card is also a good source of information.

Francis, J. A., W. Chan, D. J. Leathers, J. R. Miller, and D. E. Veron, 2009: Winter northern hemisphere weather patterns remember summer Arctic sea-ice extent. Geophys. Res. Lett., 36, L07503, doi:10.1029/2009GL037274.

Honda, M., J. Inoue, and S. Yamane, 2009: Influence of low Arctic sea-ice minima on anomalously cold Eurasian winters. Geophys. Res. Lett., 36, L08707, doi:10.1029/2008GL037079.

Overland, J. E., and M. Wang, 2010: Large-scale atmospheric circulation changes associated with the recent loss of Arctic sea ice. Tellus, 62A, 1.9.

Petoukhov, V., and V. Semenov, 2010: A link between reduced Barents-Kara sea ice and cold winter extremes over northern continents. J. Geophys. Res.-Atmos., ISSN 0148-0227.

Seager, R., Y. Kushnir, J. Nakamura, M. Ting, and N. Naik (2010), Northern Hemisphere winter snow anomalies: ENSO, NAO and the winter of 2009/10, Geophys. Res. Lett., 37, L14703, doi:10.1029/2010GL043830.

Jeff Masters

Peeking Christmas Lights in Snowy Shrub (UnobtrusiveTroll10)
At my house. Their little heat has created a tiny viewing hole.
Peeking Christmas Lights in Snowy Shrub
Berry Cold Strawberries (lshunter)
Astin Farms in Plant City, FL waters their strawberry crop to prevent damage from frost as temperatures drop into the 20s overnight on December 14, 2010. More cold temperatures expected tonight.
Berry Cold Strawberries

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Quoting GeoffreyWPB:
Hi, Mr. Wilson.


ROFLMAO and still trying to get up.
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..Yup,,RUSH is still Touring.


North American Surface Analysis
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Quoting DoverWxwatchter:


Glad you liked my try. Now that things are calm I am out. I hope all of you Florida folks enjoy the warmth seeping back tomorrow.


It is seeping slowly.
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Quoting misanthrope:




Hello Mr. Wilson!
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As long as we're in a musical mood tonight...

http://www.youtube.com/watch?v=EHoXes1M3oU
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Quoting Patrap:
RUSH

Moving Pictures?



A great album. LOL. Nice, Pat!
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Quoting KEEPEROFTHEGATE:



Keep, a little help, please. I'll stand by your judgment, without equivocation.


No worries, lay bare my nature.
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RUSH

Moving Pictures?

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634. Inyo
Quoting EnergyMoron:


U2. What is the carbon footprint of their latest tour?



Link



I know I raise complex issues. Obviously nobody wants to solve global warming but just talk about it.

Good night.


Don't forget 'the edge' of U-2 : espousing environmentalist ideals, but is directly responsible for destruction of hundreds of acres of coastal sage scrub, a habitat type almost comparable to the rain forest in biodiversity and much more rare. It seems that he likes the attention associated with promoting environmental causes, but when it comes to actually protecting endangered ecosystems and damaged watersheds, his actions speak pretty loudly.
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Quoting EnergyMoron:


U2. What is the carbon footprint of their latest tour?



Link



I know I raise complex issues. Obviously nobody wants to solve global warming but just talk about it.

Good night.


Agreed, an interesting question! At present, I have no answer. I will research it, however. Kudos.
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Quoting DoverWxwatchter:


Is that the person on the left?


No, actually that is Bengt Ekerot, a very famous Swedish actor. But good try. The guy on the right is Max von Sydow, also world famous actor from Sweden. Can't fool old Grothar!! LOL
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Quoting Jeff9641:


I thought you would like the video on post 616! Those wore the days back in middle school. That was when music was the best in the 90's


I agree. No matter what genre (except country) you listened to in the 90s, it was great music. I'm a rock person myself, but I have my fair share of hip-hop on my iPod. It's mostly from the 80s and 90s, however.
Member Since: October 8, 2008 Posts: 14 Comments: 4553
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Thanks EM. For now, I'm gonna pass and continue to drive my cars and boats, play golf and eat cow meat after they have flatulated the air and deficated the earth which eventually ends up in the water I drive my boat in and waters my golf course as I condition my air and swim in my pool in the name of capitalism. But tomorrow, maybe...
Member Since: July 30, 2010 Posts: 0 Comments: 491
Quoting BigToe:
612. Jeff9641 3:45 AM GMT on December 16, 2010
Here's another song!

http://www.youtube.com/watch?v=N5lIWti4VUw
Action: Quote | Ignore User

=========================
Still prefer the Doors.........


+1. Even though i'm 18, I always prefer the Doors to what my generation listens to. To me, it's not real music, it's mostly auto-tuned songs.
Member Since: October 8, 2008 Posts: 14 Comments: 4553
Quoting Patrap:
UNYSIS GFSx 10-day Loop


Sure love to see these visuals....KOTG where are yours?
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Quoting PSLFLCaneVet:


U2. What is the carbon footprint of their latest tour?



Link



I know I raise complex issues. Obviously nobody wants to solve global warming but just talk about it.

Good night.
Member Since: December 8, 2009 Posts: 0 Comments: 3
UNYSIS GFSx 10-day Loop
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Member Since: July 15, 2006 Posts: 169 Comments: 53296
Anyone here know if the latest run of the GFS is still depicting another possible arctic blast for Florida and the SE CONUS around the 28th or 29th of this month?

Also and on a side note.. I thought last night would strain the electrical capacity of Florida Progress around here but it is tonight instead that we are getting little mini brownouts around here. Odd, that.
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Just no more 99Lufts Balloons.
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Quoting PSLFLCaneVet:


Now we're talkin' music Geoff.
Member Since: October 8, 2008 Posts: 14 Comments: 4553
612. Jeff9641 3:45 AM GMT on December 16, 2010
Here's another song!

http://www.youtube.com/watch?v=N5lIWti4VUw
Action: Quote | Ignore User

=========================
Still prefer the Doors.........
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Quoting DoverWxwatchter:
Caneswatch try this version.

The music starts about 15 seconds into the vid.


Oh yes, very relaxing LOL
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Quoting GeoffreyWPB:


Better than anyone I know.

BRILLIANT!!
LOLOL
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Quoting GeoffreyWPB:


Better than anyone I know.


Be careful or I will send my cousin, Slow Ingmar, to sit in your tree.
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I predict that in about 20 years those of us with connections or wealth will be able to "colonize" planets of astounding beauty and totally pristine with docile creatures that we can domesticate. All forms of pleasure will be legal and there will evolve a true Utopian society for those lucky enough to go.

Vieux Carre Cam
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Quoting Jeff9641:
Too much tension on blog for so late at night. Guys get a cocktail and relax. Here is something to relax on below.

http://www.youtube.com/watch?v=a0z7OCaiByw


LOL Jeff, you call that relaxing?

This is a song I relax to:
Member Since: October 8, 2008 Posts: 14 Comments: 4553
Quoting Grothar:


They have pills for that now. I shall send you some if need be. LOL

No Need!
But I will keep you unpleasantly informed of any change in circumstance....
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.."Lights please"..
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Quoting Grothar:


Can I make a dumb statement?............


Better than anyone I know.
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Quoting KerryInNOLA:
You're at work right now. And it's summertime. What time is it?
Here is my prediction for the future.
WU member Quadrantid is zeroing in on Earth like planets.Bob Lazar says we almost have reverse engineered that space saucer they have at area 51.

I predict that in about 20 years those of us with connections or wealth will be able to "colonize" planets of astounding beauty and totally pristine with docile creatures that we can domesticate. All forms of pleasure will be legal and there will evolve a true Utopian society for those lucky enough to go.


It'd be nice :) Take us a while to get to the utopian planets, mind -- space is just too damn big!

It's just gone 2:30 here, and it's properly sticky... not so much hot as humid... not the kind of weather I'm used to as a Brit. That said, it's awesome to get proper thunderstorms :) I know severe weather warnings are a bad thing, and that it's dangerous, but it's also so beautiful and exciting... am sat gazing out of the window, watching the lightning, rather than refereeing the paper I'm meant to have finished with by Monday :S
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Quoting Grothar:
Hey,ENERGYMORON, your blog entry was longer than my first marriage.


LOL..Pa rum pum pum pum
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Quoting GeoffreyWPB:


It's like watching reruns of a TV. show. Same stuff...different day.


Can I make a dumb statement?............
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Quoting Grothar:
Hey,ENERGYMORON, your blog entry was longer than my first marriage.

LOL
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Hey,ENERGYMORON, your blog entry was longer than my first marriage.
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Quoting KEEPEROFTHEGATE:
what are ya all fighting about tonight


Bing Crosby...Was he mean to his kids?
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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

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