Remarkably dry and warm winter due to record extreme jet stream configuration

By: Dr. Jeff Masters , 4:06 PM GMT on January 06, 2012

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Flowers are sprouting in January in New Hampshire, the Sierra Mountains in California are nearly snow-free, and lakes in much of Michigan still have not frozen. It's 2012, and the new year is ringing in another ridiculously wacky winter for the U.S. In Fargo, North Dakota yesterday, the mercury soared to 55°F, breaking a 1908 record for warmest January day in recorded history. More than 99% of North Dakota had no snow on the ground this morning, and over 95% of the country that normally has snow at this time of year had below-average snow cover. High temperatures in Nebraska yesterday were in the 60s, more than 30° above average. Storm activity has been almost nil over the past week over the entire U.S., with the jet stream bottled up far to the north in Canada. It has been remarkable to look at the radar display day after day and see virtually no echoes, and it is very likely that this has been the driest first week of January in U.S. recorded history. Portions of northern New England, the Upper Midwest, and the mountains of the Western U.S. that are normally under a foot of more of snow by now have no snow, or just a dusting of less than an inch. Approximately half of the U.S. had temperatures at least 5°F above average during the month of December, with portions of North Dakota and Minnesota seeing temperatures 9°F above average. The strangely warm and dry start to winter is not limited to the U.S--all of continental Europe experienced well above-average temperatures during December.


Figure 1. Flowers sprouting on January 1, 2012 in Keene, New Hampshire, thanks to unusually warm December temperatures and lack of snow. Image credit: Wunderphotographer lovne32.


Figure 2. Departure of snow depth from average on January 6, 2011. More than 95% of the country that normally has snow at this time of year had below-average snow cover (yellow and orange colors.) Image credit: NOAA/National Operational Hydrologic Remote Sensing Center.

December 2011 jet stream pattern the most extreme on record
The cause of this warm first half of winter is the most extreme configuration of the jet stream ever recorded, as measured by the North Atlantic Oscillation (NAO). The Arctic Oscillation (AO), and its close cousin, the North Atlantic Oscillation (which can be thought of as the North Atlantic's portion of the larger-scale AO), are climate patterns in the Northern Hemisphere defined by fluctuations in the difference of sea-level pressure in the North Atlantic between the Icelandic Low and the Azores High. The AO and NAO have significant impacts on winter weather in North America and Europe--the AO and NAO affect the path, intensity, and shape of the jet stream, influencing where storms track and how strong these storms become. During December 2011, the NAO index was +2.52, which was the most extreme difference in pressure between Iceland and the Azores ever observed in December (records of the NAO go back to 1865.) The AO during December 2011 had its second most extreme December value on record, behind the equally unusual December of 2006. These positive AO/NAO conditions caused the Icelandic Low to draw a strong south-westerly flow of air over eastern North America, preventing Arctic air from plunging southward over the U.S. and Europe.




Figure 3. December 2011 temperatures in Europe and the U.S. were well above average, thanks to a positive phase of the Arctic Oscillation (AO). Compare the U.S. plot with the plot of typical departures of temperature from average due to the positive phase of the AO (Figure 4.) The two patterns are nearly identical. Image credit: NOAA/ESRL.


Figure 4. The departure of temperature from average in Centigrade during the November - December - January period during various phases of the Arctic Oscillation (AO). Positive AO conditions lead to warm winters in the U.S., while negative AO conditions lead to cold winters. Image credit: NOAA/Climate Prediction Center.

Wild swings in the December Arctic Oscillation
This winter's remarkable AO/NAO pattern stands in stark contrast to what occurred the previous two winters, when we had the most extreme December jet stream patterns on record in the opposite direction (a strongly negative AO/NAO). The negative AO conditions suppressed westerly winds over the North Atlantic, allowing Arctic air to spill southwards into eastern North America and Western Europe, bringing unusually cold and snowy conditions. The December Arctic Oscillation index has fluctuated wildly over the past six years, with the two most extreme positive and two most extreme negative values on record. Unfortunately, we don't understand why the AO varies so much from winter to winter, nor why the AO has taken on such extreme configurations during four of the past six winters. Climate models are generally too crude to make skillful predictions on how human-caused climate change may be affecting the AO, or what might happen to the AO in the future. There is research linking an increase in solar activity and sunspots with the positive phase of the AO. Solar activity has increased sharply this winter compared to the past two winters, so perhaps we have seen a strong solar influence on the winter AO the past three winters. Arctic sea ice loss has been linked to the negative (cold) phase of the AO, like we observed the previous two winters. Those winters both had near-record low amounts of sunspot activity, so sea ice loss and low sunspot activity may have combined to bring a negative AO.


Figure 5. The December Arctic Oscillation (AO) index has fluctuated wildly over the past six years, with the two most extreme positive and two most extreme negative values on record. Image credit: NOAA/Climate Prediction Center.

The forecast for the remainder of January
We will (finally!) get the first major storm of 2012 in the U.S. early next week, when a low pressure system will develop over Texas and spread heavy rains of 1 - 3" along a swath from Eastern Texas to New England during the week. This storm will pull in a shot of cold air behind it late in the week, giving near-normal January temperatures to much of the country, and some snow to northern New England. Beyond that, it is difficult to tell what the rest of winter may hold, since the AO is difficult to predict more than a week or two in advance. The latest predictions from the GFS model show the current strongly positive AO pattern continuing for at least the next two weeks, resulting in very little snow and warmer-than-average temperatures. If we don't get significant snows during the latter part of winter, the odds of a damaging drought during the summer in the Midwest will rise. The soils will dry out much earlier than usual without a deep snow pack to protect them, resulting in a much earlier onset of summer-like soil dryness. Water availability may also be a problem in some regions of the west due to the lack of snow melt. Fortunately, most Western U.S. reservoirs are above average in water supply, due to the record-breaking snows of the previous winter.

Jeff Masters

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Quoting Snowbody:


In the given example, no one would argue that an inability to do math motivates the decision to do so...not greed.




$62,500/year then.


If one and a half chickens lay one and a half eggs in one and a half days than how many eggs do 9 chickens lay in 9 days?
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Per capita, China and India's emissions are much less than ours. China has a larger population than Europe, North America, and Japan and Australia combined. India soon will. What we will find out is whether the climate system can handle large and rapidly increasing greenhouse gas emissions from those countries and other developing countries without significant warming. I'm guessing the answer will be no.

Quoting BobWallace:


My point is, when we in the US complain about China's and India's CO2 emission we're like a guy dumping is garbage can on the sidewalk while complaining about someone else dropping a gum wrapper.

As for the Chinese sending their 'best and brightest' to the US to get their educations, they've done it. They have educated their best at government expense.

We, on the other hand, have burdened our 'best and brightest' with enormous debt.

Remember how the US got ahead by educating a generation with the GI Bill? Remember how we lead the world for a few decades largely due to that modest investment in our youth?
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Member Since: July 15, 2006 Posts: 178 Comments: 56059
Quoting presslord:


OK...let's say you make $50,000 per year working forty hours per week....by working an additional 10 hours per week you can make $60000 per year....and you choose to do so....I would argue that a positive form of greed motivates that decision...yet you haven't exploited anyone in the process...


In the given example, no one would argue that it's an inability to do math that motivates the decision to do so...not greed.


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I'm sure it's not so, but it really feels like this is the cloudiest the GOM has been since TS Lee....
Member Since: October 25, 2005 Posts: 19 Comments: 22728
There's the low-pressure area that will bring Severe Weather/Tornadoes across TX, LA, MS, and AL, along with Heavy rain across the rest of the East Coast in the top left corner.

Member Since: July 6, 2010 Posts: 113 Comments: 32823
Quoting JNCali:
Not sure about your point with per capita emissions... a thousand metric tons is a thousand metric tons.. as to Chinese manufacturing.. the Economist has an available article online that may help if you are interested Link.. many people like to make the US out to be the Bad Guy.. the problem is that all the other countries have sent their 'best and brightest' to the US to get their educations so really it comes down to who has the best marketing.. imho
Clear and mild here in Mid TN with a chance of rain tonight...


My point is, when we in the US complain about China's and India's CO2 emission we're like a guy dumping is garbage can on the sidewalk while complaining about someone else dropping a gum wrapper.

As for the Chinese sending their 'best and brightest' to the US to get their educations, they've done it. They have educated their best at government expense.

We, on the other hand, have burdened our 'best and brightest' with enormous debt.

Remember how the US got ahead by educating a generation with the GI Bill? Remember how we lead the world for a few decades largely due to that modest investment in our youth?
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Member Since: July 6, 2010 Posts: 113 Comments: 32823

SH992012 - INVEST

Multiplatform Satellite Surface Wind Analysis

Member Since: July 3, 2005 Posts: 428 Comments: 129841
Quoting TropicalAnalystwx13:
This is probably close to being designated as a tropical cyclone. It will bring torrential rainfall to Madagascar regardless or whether it is designated or not.


And with that comes the first operational test of the RI script...

As of Jan 7th at 0Z, 2012, 99S.INVEST has a low chance (15%) of rapidly intensifying in the next 24 hours.

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This is probably close to being designated as a tropical cyclone. It will bring torrential rainfall to Madagascar regardless or whether it is designated or not.



Soo much stuff to talk about...Severe Weather, Winter Weather, Tropical Weather.
Member Since: July 6, 2010 Posts: 113 Comments: 32823
Quoting TropicalAnalystwx13:
Don't worry guys, it is going to get a lot colder....Give it another week and a half or so.


Aww..I was enjoying the rain we got up here in the north today. :( I don't want it to go back down to -30C!
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A potent tornado outbreak is looming for Texas, Louisiana, and Mississippi on Monday/Tuesday as the significant cutoff low a lot of us have been talking about enters the region. Dr. Forbes has already given a TOR:CON index of 5 out of 10, and the parameters look to be there for many tornadoes, some of which could be large and long-lived. This is definitely more characteristic of an March/April outbreak instead of a January one.

Member Since: July 6, 2010 Posts: 113 Comments: 32823
Quoting TropicalAnalystwx13:
Don't worry guys, it is going to get a lot colder....Give it another week and a half or so.


ya the GFS looks promising :D
Member Since: August 4, 2011 Posts: 46 Comments: 4488
Don't worry guys, it is going to get a lot colder....Give it another week and a half or so.
Member Since: July 6, 2010 Posts: 113 Comments: 32823
Quoting BahaHurican:
Evening all.

Do u guys get a freeze on the lake there most winters? My mind is telling me it's fairly deep...


Usually get a pretty good icing over the lake and the smaller ones go solid.. Not this time. It's like April here, Not January... very disappointing really. And they even drained the lake way down in anticipation of heavy snow melt.. looks like that will now be a problem.
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148. j2008
Quoting Patrap:
Gulf of Mexico

RGB animated Loop

..click image for Loop


If this was cane season I'd say that looks like a SS in formation, ohh my its Lee part 2! LOL I'm really looking foward to the TCR of Rina and Sean both of them could be very intresting.
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Quoting ChillinInTheKeys:


They did a great job of instilling Agnosticism in a lot of us!!!


You was right! Didn't work. (
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It got into the lower 60's today in Cincy. WHERE'S MY WINTER!?!?!
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Quoting BahaHurican:
[snicker] How much do u want 2 bet Emily's the last one they do.... lo



TS Emily was pathetic 100%. from the first dayit was lookin terrible i wa wishin it would go ahead and dissipate so i ddint have to look at it anymore lol
Member Since: August 4, 2011 Posts: 46 Comments: 4488
Quoting Neapolitan:
The TCR on the mighty Jose was just released. Top winds are still listed at 40 knots, though the system's life as a tropical storm was longer than initially thought. Because its life was extended, ACE has been raised to 0.8475, moving it ahead of TS Lee; it nows shares 16th place on the season with September's unnamed TS.

We're still waiting on TCRs for Katia. Rina, Maria, Sean, and Emily.
[snicker] How much do u want 2 bet Emily's the last one they do.... lo

Member Since: October 25, 2005 Posts: 19 Comments: 22728
Ok you Saints and sinners. I have to go. I hope you all get all the snow you want or whatever frosts your cookie. If anything interesting happens, (highly unlikely) please drop a line. I can't get on too much. Ciao!
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Quoting ChillinInTheKeys:


They did a great job of instilling Agnosticism in a lot of us!!!


I don't know about that, but I'll believe it when I see it. :)
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Quoting Grothar:


Very true!! I never consumed any alcohol. I still don't. (for real) Although I seem to recall some guys from Louisiana back in 1984 really had a good time with it.


Ice was required at one point, so your point is well "remembered".
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Also "note" the Smaller Vortex in the Eastern GOM, Sw of Tampa.

ZOOM is available, click on animated Loop to ZOOM
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Quoting washingtonian115:
This winter suuuuuucks so badly.


There is hope for snow here on Monday.
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Quoting Patrap:


is that true?



..you could go Blind without having had one ya know?


Very true!! I never consumed any alcohol. I still don't. (for real) Although I seem to recall some guys from Louisiana back in 1984 really had a good time with it.
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Quoting Patrap:
Gulf of Mexico

RGB animated Loop

..click image for Loop



Did you notice that little spin hangin' around all day SW of Tampa?
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Gulf of Mexico

RGB animated Loop

..click image for Loop

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Quoting Grothar:


Didn't work, huh?


They did a great job of instilling Agnosticism in a lot of us!!!
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Quoting Grothar:


Never had one!


is that true?



..you could go Blind without having had one ya know?
Member Since: July 3, 2005 Posts: 428 Comments: 129841
This winter suuuuuucks so badly.
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Quoting WxGeekVA:


What is this and why does it look better than half of our storms this year...

Maybe on satellite..it just doesn't have deep convection.
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Quoting Patrap:
Mack-O is not in Fla.


Never had one!
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NOLA Long Range Disco..



Long term...

the aforementioned slow moving cold front will become quasi stationary across the Gulf Coast states...but to the north of the local forecast area...Saturday into Saturday night as it becomes more or less parallel to the flow aloft.

However...the boundary may sag southward into the extreme northern and northwestern sections of
the forecast area Sunday and Sunday night. Large scale forcing and lift will be largely absent across the region during the course of the weekend.

..however will still continue to mention a slight chance of showers during the period due to the proximity of frontal boundary where weak convergence will exist...moisture will continue to pool...and a couple of weak disturbances in the flow aloft will traverse the lower Mississippi Valley and Gulf Coast regions.


Energy dropping into the Pacific northwest and across The Rockies through the weekend is forecast to evolve into a closed low over western Texas late in the weekend and at the beginning of next week.

This rather potent system is then forecast to move east across the lower Mississippi and Gulf Coast region during the early and middle part of next week.

Although there has been some consistency issues with the models with the exact movement of this
system...it does appear at this time there there could be some severe weather threat across the region Tuesday with the forecast area possibly being in the warm sector for a relatively brief period of time.
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Evening all.

Quoting Sandpoint21:
The Winter for Sandpoint, ID is dead...
Do u guys get a freeze on the lake there most winters? My mind is telling me it's fairly deep...
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Quoting KEEPEROFTHEGATE:
so are you where you said you be


No, I am someplace else, but was there before I came here.
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Quoting Patrap:












What is this and why does it look better than half of our storms this year...
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Quoting ChillinInTheKeys:
I did a tour at St. Stanislaus boarding school in "73" as an attempted attitude adjustment.


Didn't work, huh?
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Quoting Grothar:
Look, I can only stay up for a few more minutes. I have to get to bed. It is very late here. Anyone who has anything to say, say it fast. Anyone know if the states are going to get any storms or anything this coming week?
tuseday night wed and again starting friday
Member Since: July 15, 2006 Posts: 178 Comments: 56059
Quoting WxGeekVA:


Boy, am I glad I go to public school.... I have a temper and I would probably and unfortunately get kicked out of a Catholic school.


i am homeschooled. i got a punchin bag for Christmas to beat it up when i boil over lol. a bit more aggressive then the average guy i guess. xD
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Mack-O is not in Fla.
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Quoting Inyo:
I have to say the quality of conversation in these blog comments is much more civil and respectful than usual. Who knew?


Strange abnormal weather, strange abnormal behavior............

I am sure it will change just like the weather does..........
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Quoting Grothar:
Look, I can only stay up for a few more minutes. I have to get to bed. It is very late here. Anyone who has anything to say, say it fast. Anyone know if the states are going to get any storms or anything this coming week?
so are you where you said you be
Member Since: July 15, 2006 Posts: 178 Comments: 56059
Quoting 1911maker:


While I will not agree with Grothar that it is/was all good, the Nuns would probably not "kick you out", but I expect you would be gently reminded that temper is a bad response. :) Yes ever so gently.

Battle tested Marines tended to say "Yes Sir" to an "old school" Nun.


LOL
Member Since: September 3, 2011 Posts: 13 Comments: 3477
Look, I can only stay up for a few more minutes. I have to get to bed. It is very late here. Anyone who has anything to say, say it fast. Anyone know if the states are going to get any storms or anything this coming week?
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I did a tour at St. Stanislaus boarding school in "73" as an attempted attitude adjustment.
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Quoting Inyo:
I have to say the quality of conversation in these blog comments is much more civil and respectful than usual. Who knew?


Mind your own business!! j/k
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Quoting WxGeekVA:


Boy, am I glad I go to public school.... I have a temper and I would probably and unfortunately get kicked out of a Catholic school.


While I will not agree with Grothar that it is/was all good, the Nuns would probably not "kick you out", but I expect you would be gently reminded that temper is a bad response. :) Yes ever so gently.

Battle tested Marines tended to say "Yes Sir" to an "old school" Nun.
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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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