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While Most of U.S. Froze, Parts of Alaska Set Record Highs

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While the continental U.S. has been shivering from coast-to-coast with temperatures dropping as low as minus-40°F amid one of the most severe early December cold snaps in several years, one state bucked the trend in an historic way. The same contorted jet stream pattern that brought the brutal cold to the lower 48 states pushed a pulse of milder-than-average air into Alaska, where some spots recorded temperatures unheard of for December.

Map showing temperature anomalies in the atmosphere, including notes showing the unusually warm air over Alaska (red area) and cold air from Canada to the U.S. (dark blue area). 
Click image to enlarge. Credit: Modified from Tropicaltidbits.com via WeatherUnderground.

Along Alaska's northern coastline, which lies above the Arctic Circle, the warmest December temperatures on record in at least 70 years occurred this past week. At the airport in Deadhorse, which serves the oil production hub of Prudhoe Bay, the temperature hit 39°F on December 7, the highest December temperature on record there since at least 1968, said Rick Thoman of the National Weather Service (NWS) in Fairbanks in an interview. Even more notable, perhaps, was the fact that it was raining, rather than snowing. Rain there is unusual so late in the year.

Previously, the highest December temperature recorded at any of the two climate observation sites that have served Prudhoe Bay over the years was 35°F, set on Dec. 31, 1973, according to Chris Burt, a blogger at WeatherUnderground.

Thoman said it’s possible, but not likely, that other climate stations in that area — such as data collected at now defunct Cold War-era early warning radar stations — recorded slightly milder December temperatures when they were operating in the 1950s and 1960s.

December high temperature records were also set or tied at Barter Island AFB, which is a tiny airport located on a sliver of land along Alaska’s wind-whipped North Slope region, and in the small village of Wainwright, another Arctic shore location. Barter Island reached 37°F, which tied its record last set in 1973, and Wainright hit 32°F, beating the old record of 30°F last set in 2006.

Some weather stations located along the Dalton Highway south of Prudhoe Bay saw temperatures climb into the 40s, Thoman said.

Other noteworthy Alaska records included a December record high of 54°F in King Salmon, which is situated along Bristol Bay in southwest Alaska. That broke the previous record of 51°F, and records there date back to World War II. Daily high temperature records were also set at Kotzebue, Bettles, and Cold Bay, Alaska, among other locations, Thoman said.

The first nine days of December ran 22.2°F above average in Barrow, and 18.5°F above average in Kotzebue, according to NWS data.

A strong ridge of high pressure was the main cause of the record warmth in Alaska. The high shunted the jet stream, which is a high speed current of winds in the upper atmosphere, to the north of the state, while simultaneously displacing cold, Arctic air southward into Canada and the continental U.S.

Thoman said such weather patterns are not uncommon during the winter months, although the extreme nature of this one was. “This kind of thing does happen with some frequency in the cold season,” Thoman said. “You get these amplified patterns, and the cold air’s gotta go somewhere, so you build up the ridge somewhere over the Gulf of Alaska . . . pump warm air into Alaska, and on the east side of that high, that cold air is going to come plunging south.”

The small northern Alaska community of Wainwright, pictured during the summer. 
Credit: Wikimedia Commons.

In recent years, studies have shown an association between extremely wavy or “amplified” jet stream patterns, with large ridges and troughs, and Arctic sea ice melt and snow cover decline during the spring and summer months. It's an active area of research, but there’s no doubt that climate change has been having profound impacts in Alaska and other areas of the Arctic region.

The 2012 Arctic Report Card depicted a region undergoing rapid and pervasive changes related to manmade global warming, including the ramifications from plummeting spring and summer sea ice cover, melting permafrost, a rapid loss of spring snow cover, and various other climate change impacts. The 2013 edition of the Report Card, published by the National Oceanic and Atmospheric Administration, will be released on Thursday.

Recent news reports from Alaska show that increasingly mild fall seasons and erratic weather patterns have had significant effects on local communities.

For example, In Wainwright, changes in weather patterns have diminished the opportunities for subsistence hunters to safely hunt whales and caribou during the fall harvest season, according to a new study published in the journal Arctic.

Alaskans have also seen a precipitous decline in the Western Arctic Caribou Herd, which is thought to be a result, at least in part, of an increase in fall freezing rain events. A colder atmosphere used to produce more snow events, but ice storms have become more common along the caribou’s migration routes, which is helping to thin the herd, according to reporting by the Alaska Dispatch.

Although the long-term forecast calls for continued warming during the next several decades, in the near term, the high pressure area over Alaska is weakening, allowing colder air and snowier weather to return to the Frontier State, Thoman said.

The upcoming weather pattern will be “A big change from what we’ve had, that’s for sure,” Thoman said.

Related Content
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Arctic Blast Has Half the Lower-48 States In Its Icy Grip
New Study Adds to Global Warming, Extreme Weather Debate
For First Time in 20 Years, Cold Records May Beat Warm
Snow Cover May Help Usher in Historic Cold to Northwest

Comments

By Eric Peterson (Front Royal, VA 22630)
on December 10th, 2013

“Although the long-term forecast calls for continued warming during the next several decades,...”

Alaska, with the minor except of the north coast, has been cooling for over a decade.  A more likely forecast is continued cooling, also including the north coast as residual Arctic ocean warmth runs out.  The Arctic as a whole has warmed rapidly for about 30 years: http://images.remss.com/data/msu/graphics/TLT/plots/RSS_TS_channel_TLT_Northern Polar_Land_And_Sea_v03_3.png but that seems to be part of a cycle of warming which is peaking like planetary warming, except the Arctic peaks later than the rest of the world.

Reply to this comment

By Andrew
on December 10th, 2013

Eric, while Alaska has been cooling during the past decade (with the exception of far northern regions of the state), the 30-year trend is still positive (http://data.giss.nasa.gov/cgi-bin/gistemp/nmaps.cgi?year_last=2013&month_last=10&sat=4&sst=3&type=trends&mean_gen=0112&year1=1980&year2=2012&base1=1981&base2=2010&radius=250&pol=pol). Also, I don’t know of a single climate study in the peer reviewed literature that projects a peak Arctic warming followed by cooling in the near future, as you indicate. If you’re right, you’ll be due for some major awards for your outlier prediction.

Reply to this comment

By Eric Peterson (Front Royal, VA 22630)
on December 10th, 2013

Andrew, thanks for the reply.  You can see from the trend line (no trend) that Leif Svalgaard likes to put on his charts: http://www.leif.org/research/Ap-1844-now.png that there is no question that solar is not a component of very long term warming over the past 150 years or so.  That is strong evidence for manmade greenhouses gases.  However the variation in the solar chart matches the variations in global temperature with a lag of a decade or so.  A lag of some amount would result from ocean thermal inertia.  So while the trend may be up over the long run, there might be a dip or two along the way.

I am hardly the first person to make a prediction of upcoming cooling due to the decline in solar activity and do not deserve any awards.  I merely point it out as a heads up to folks who read this blog and have never heard any alternatives other than catastrophic warming is on the way.  That may be true in the long run (end of the century).  Also nobody can predict what the sun is going to do past a few years to maybe a decade or so.

Reply to this comment

By Phil Mattheis (41091)
on December 11th, 2013

Eric, you provide no reference to show cooling in Alaska, and the graph you link gives no indication of approaching cooling in the arctic temp trend.  What you got to support the claim “...as residual Arctic ocean warming runs out”?

Alaska is full of pretty independent folks, who mostly hold pretty conservative views of the world. However, “Alaska has been cooling for over a decade” would not be among them. Most glaciers in the state are losing mass (rapidly), permafrost is melting throughout the interior as well as arctic, sea ice is thinner and disappearing faster all along the coast and beyond. Spring comes now a week or two earlier in central and southern Alaska, and winter holds off a week or two on the other end. Last summer had record highs all over the place, including 90’s on the Kenai Peninsula, back up in the woods in June…

You might need to be a little more careful about your sources of information.

Reply to this comment

By kermit
on December 11th, 2013

Speaking for myself, Eric, I am only interested in alternatives that are based on verifiable evidence. We know how much heat is being retained over the normal (recent pre-industrial millennia) and it corresponds well to the heat-retention characteristics of greenhouse gases. There is a very small temperature variation due to solar cycles but those effects are swamped by the warming trend of anthropogenic greenhouse gases and the additional feedback loops and forcings induced by that.

I am afraid that nobody will be awarded for having predicted near-term cooling.

Reply to this comment

By George Birchard (Sanford, NC)
on December 11th, 2013

Siberian temperatures have also been well above normal for the past month. The continental U.S. is on the cold end of a jet stream pattern that has led to well above normal temperatures across most of the northern hemisphere outside of the tropics.

The claim that the Arctic will soon be cooling because there’s a ocean caused lag cannot be true because the oceans are heating up. Growing amounts of heat stored in the oceans point to continued warming.

Reply to this comment

By Eric Peterson (Front Royal, VA 22630)
on December 13th, 2013

Phil, here’s a paper about the cooling in Alaska: http://www.benthamscience.com/open/toascj/articles/V006/111TOASCJ.pdf You are correct about spring coming earlier, and melting in general, but those are lagging indicators and will turn around later.

kermit, we are missing about half the supposedly retained heat, currently we see about 1/2 W/m2 instead of the 1W/m2 that we expect.  One possiibility is even more ocean warming than is estimated by Levitus et al since Levitus warming can’t account for all the sea level rise.  See fig 1 here: http://www.cgd.ucar.edu/cas/Trenberth/website-archive/trenberth.papers-moved/Balmaseda_Trenberth_Kallen_grl_13.pdf and the conclusion: “The magnitude of the warming trend is consistent with observational estimates, being equivalent to an average 0.47 ` 0.03 W m–2 for the period 1975–2009. There is large decadal variability in the heat uptake, the latest decade being significantly higher (1.19 ` 0.11 W m–2) than the preceding record. Globally this corresponds to 0.84 W m–2, consistent with earlier estimates [Trenberth et al., 2009]”  Trenberth is careful not to put too much stock in the new Levitus estimates but suggests the ocean is a possible location of the missing heat.

Reply to this comment

By Steven Blaisdell
on December 15th, 2013

“those are lagging indicators and will turn around later.”
For this you’d have to show some kind of lasting negative feedback currently in action; not that negative feedbacks don’t exist but all evidence points the other way. Decadal patterns, as you know, are not predictive of climate. Wendler, et al. could possibly be showing a turn back to a cooler local climate; indicators other than surface temps from only 11 stations (a shortcoming admitted by the paper’s authors) indicate otherwise. To say that well-advanced, geologic signs and effects of warming will somehow “turn around later” begs a larger understanding of scale and ecology.

Further, as Wendler concludes: ” In summary, the long term observed warming of Alaska of about twice the global value, as expected by the increasing CO2 and other trace gases, is sometimes temporarily modified or even reversed by natural decadal variations.” Barring a miraculous turnaround in global CO2 emissions, it seems counter intuitive the paper shows anything other than such a decadal variation, a return to the mean before continued warming (that is , if the data are indicative - for more on measurement-based underestimation of surface warming, please see:
http://onlinelibrary.wiley.com/doi/10.1002/qj.2297/abstract

I understand the desire to see a break from the increasingly bad news about rapidly changing climate. I don’t think the Wendler paper goes very far in reversing this trend.

Reply to this comment

By Eric Peterson (Front Royal, VA 22630)
on December 13th, 2013

George, it is true the oceans are warming.  However they are warming about ha;f the rate expected for the long term radiative imbalance from CO2 (see link in my previous post).  That is, 0.5 W/m2 of warming (globally averaged) stored in the oceans is not enough to cause continued warming of the atmosphere even all or most of the heat could return.

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