bluewave

It's funny how the pattern reversed right after the paper was published. http://onlinelibrary.wiley.com/store/10.1029/2012GL053268/asset/grl29604.pdf;jsessionid=F7950891CB18B3DB5580C02EC912A4A1.f01t03?v=1&t=j4ppf2qo&s=29436c163ab48e25e8f4989445de41091a8d6ccd&systemMessage=Wiley+Online+Library+'Journal+Subscribe+%2F+Renew'+page+will+be+down+on+Wednesday+05th+July+starting+at+08.00+EDT+%2F+13.00+BST+%2F+17.30+IST+for+up+to+75+minutes+due+to+essential+maintenance. Thus we can say that a six year run of near one standard deviation negative excursions (2007–2012) is unique in the 63 year record. To further test the significance of the 2007–2012 AD patterns we randomly generated 10,000 time series, each with 63 points to match the observed time series and with a normal distribution without autocorrelation. For this simple calculation, the chance for having five consecutive values with a negative AD of magnitude greater than 1.0 standard deviation units in a sample size of 63 is rare, less than 1 in a 1000.

While the overall annual temperature trend is an unmistakable up, it would be interesting to know what changed after the 2012 summer. To get a 6 year historic stretch of dipole patterns during the summer and then a reversal is pretty extreme 500 mb behavior.

June officially continues the post 2012 pattern of a more active polar vortex and cooler temps.You can see the long range ensembles continuing this general pattern right into July.

You are right. That was probably the better example of Volume vs extent divergence. 2007 was the year of the mega dipole. Remarkable how a version of the summer pattern repeated much of the time until 2012 and then abruptly reversed.

It's interesting how big a difference the extents can vary with similar volume depending on weather conditions. We saw the divergence between 11 and 12 extents on similar volume due to the much more hostile weather pattern in 12.

JAXA looks like it's on target to finish very close to last year if there is an average 2007-2016 melt rate for the rest of the summer.

IMHO the 2005-2007 period pretty much reset the whole Arctic background state. Arctic amplification really took off at that time when the September avg extents started regularly falling below 6 million sq km on NSIDC. We didn't even need a 2012 record minimum the last few years to set the extreme Arctic warmth records.

We would need a solid dipole pattern to lock in to have a chance of challenging 2012. Otherwise, it's going to be another year that the 2012 record holds. Seems like the really extreme Arctic conditions for the most part since 2012 have been during the winters instead of the summers from 2007-2012.

If this cooler pattern continues, then it might not really matter if we know the exact volume for sure. 2012 and 2011 weren't all that different on volume in August and September. But the 2012 record warmth with the weather pattern made all the difference between the two extent finishes in September. This June is continuing the post 2012 stronger polar vortex pattern vs the 2007-2012 raging dipole regime. We would need a July 2015 rapid reversal to really accelerate the melt. But that kind of reversal isn't showing up in the longer range guidance as of yet. Even Greenland is enjoying a below average melt compared to recent years.

PIOMAS actually pulled back closer to the pack the last few weeks.

More uncertainty about the actual thickness this year due to the divergence between PIOMAS and CryoSat. NSIDC mentioned it in a recent discussion. Data from the European Space Agency’s CryoSat-2 satellite indicate that this winter’s ice cover may be only slightly thinner than that observed at this time of year for the past four years. However, an ice-ocean model at the University of Washington (PIOMAS) that incorporates observed weather conditions suggests the volume of ice in the Arctic is unusually low.

Coolest first half of June at Utqiaġvik (Barrow) since 1974, 4.5°F (2.5°C) below the 1981-2010 normal. You know the weather patterns are really out of whack when it's 36 on January 1st in Barrow and can only reach a high of 38 degrees during the first half of June. https://mobile.twitter.com/AlaskaWx/status/875793934043291648/photo/1#

Yeah, the flip occurred right around the record breaking March 2013 -3.185 AO. That's when the dominant blocking shifted from the Atlantic to Pacific sector. The +PDO recently set a record breaking 40 positive months in a row.Must be related to AGW, Arctic, tropics, Atlantic, Pacific ,and rossby wave linkages.

The -425 m PV is one of the strongest that we have seen in June. So yet another June post 2012 without the strong 2007-2012 dipole making an appearance.

I don't think that reaching technically ice free in September is the important benchmark to focus on. The key number appears to have been dropping below 6 million sq km on a regular basis around 2005 in September. That's when Arctic amplification really took off.

Month...Year...Station...Rank 3...2010...EWR...7...NYC...6...LGA...5...JFK...4...BDR...2...ISP...3 4...2010...EWR...1...NYC...1...LGA...1...JFK...1...BDR...2...ISP...2 5...2010...EWR...4...LGA...5...JFK....4...BDR...4...BDR...4...ISP...5 6...2010...EWR...2...NYC...4...LGA...2...JFK...1...BDR...2...ISP...1 7...2010...EWR...3...NYC...2...LGA...1...JFK...1...BDR...3...ISP...2 8...2010...EWR...10...LGA...8...BDR...10 9...2010...EWR...5...LGA...6...JFK...7...BDR...7...ISP...7 ............................................................................................... 4...2011...EWR...10 6...2011...EWR...9 7...2011...EWR...1...NYC...5...LGA...10...JFK...2...BDR...4...ISP...3 9...2011...EWR...7..LGA...10...BDR...4....ISP...4 11..2011..EWR..5...NYC...6...LGA...6...JFK...5...BDR...3...ISP...4 12..2011..EWR...5...NYC...5..LGA...5....JFK...7...BDR...3...ISP...6 ................................................................................................ 1...2012...BDR...8...ISP...7 2...2012...EWR...3...NYC...2...LGA...2...JFK...1...BDR...1...ISP...2 3...2012...EWR...1...NYC...2...LGA...1...JFK...1...BDR...1...ISP...2 4...2012...LGA....4...JFK...4...BDR...3...ISP....4 5...2012...EWR...7...JFK...3...BDR...3...ISP...3 7...2012...EWR...5...JFK...6...BDR...7...ISP...7 12..2012..EWR..10...LGA..8..JFK...10...BDR...7...ISP...5 ................................................................................................ 7...2013...EWR...5...NYC...8...LGA...3...JFK...3...BDR...1...ISP...2 ................................................................................................ 12..2014..BDR...10...ISP...9 ................................................................................................. 5...2015...EWR...2...NYC...2...LGA...3...JFK...2...BDR...2...ISP...3 8...2015...EWR...7....NYC...4...LGA...4...JFK...2...BDR...3...ISP...4 9...2015...EWR...3...NYC...1...LGA...2...JFK...1....BDR...1...ISP...1 11..2015..EWR...1...NYC...1...LGA...3...JFK...2...BDR...4...ISP...1 12..2015...EWR..1...NYC...1...LGA...1...JFK...1...BDR...1...ISP...1 ................................................................................................. 3...2016...EWR...3...NYC...4...LGA...3...JFK...3...BDR...3...ISP...2 7...2016...EWR...9...LGA...4...JFK....5...BDR...5...ISP...5 8...2016...EWR...2...NYC...3...LGA...1...JFK...1...BDR...1...ISP...2 9...2016...EWR...3...NYC...5...LGA...3...JFK...5...BDR...2...ISP...5 10..2016..BDR..9...ISP...8 11..2016..EWR..9...LGA...5...JFK...7...BDR...10 ............................................................................................... 1...2017...EWR...10...LGA...6...JFK...6...BDR...1...ISP...6 2...2017...EWR...1....NYC...2...LGA...1...JFK...1....BDR...2...ISP...3 4...2017...EWR...4...NYC...2...LGA...2....JFK...2...BDR....2...ISP...1 9...2017...EWR..10..LGA...8...JFK...7....BDR...8...ISP...4 10..2017..EWR...1..NYC..1....LGA...1....JFK...2...BDR..1...ISP...1 ..................................................................................................... 2...2018...EWR...2....NYC...1...LGA....2....JFK...3....BDR...3.....ISP....1 5...2018...EWR...6....NYC...6...LGA....2....JFK...5....BDR...4.....ISP....4 8...2018...EWR...5....NYC...9...LGA....2....JFK...5...BDR....2.....ISP....4 9..2018....EWR...7....LGA...6...JFK.....8....BDR..6...ISP.....3 ...................................................................................................... 4.....2019....EWR...10...NYC...8...LGA...10...JFK...10...BDR...9.....ISP...5 7.....2019....EWR...7.....NYC..10...LGA...3....JFK....4....BDR...3.....ISP...2 9.....2019....LGA...8 10...2019....EWR...9...ISP...#7 .................................................................................................................... 1....2020...EWR...9...NYC...9...LGA....7...JFK...6...BDR...3....ISP...6 2....2020...EWR...6...NYC...6...LGA....8...JFK...4...BDR...5....ISP...3 3....2020...EWR...7...NYC...8...LGA....5....JFK...5...BDR...3...ISP...5 6....2020...EWR..10..LGA...3...BDR...5.....ISP....5 7....2020...EWR...5...NYC...7...LGA...1.....JFK...4...BDR....1...ISP....4 8....2020...EWR...10..LGA...5...BDR...3...ISP....6 11..2020...EWR....4...NYC...1....LGA....1...JFK...4...BDR...5....ISP....4 ................................................................................................................. 3....2021...LGA.....9....JFK....10.....BDR....8 6….2021….EWR…..2…..NYC….6……LGA……5…..BDR….ISP…..6 8….2021….EWR…..2…..LGA…..6…..JFK……10…..BDR….3…..ISP….5 9…2021…..EWR…..4…..LGA…..7…..JFK……7……..BDR…..5….ISP….4 10..2021….EWR…..1…..NYC…..6…..LGA….3……..JFK……3….BDR…..3…..ISP….2 …………………………………………………………………………………………………………………. 7…..2022……EWR…..#2….LGA…..#6….JFK….#4…..BDR…#10….ISP….#7

Endless summer...

It's so warm up there that we actually just had a small daily loss in extent on NSIDC.

The Arctic stations data for October shows the unprecedented nature of the extreme warmth. Chart courtesy of Richard James http://ak-wx.blogspot.com/2016/11/arctic-warmth.html

New record low October average extent of 6.40 million sq km. This beats the previous October 2007 record by 400K.

This Brian Brettschneider 925 mb October temperature chart shows how extreme this record warmth was in both absolute value and aerial coverage across the Arctic. As impressive a warm Arctic, cold continent(Eurasia) pattern that you are going to see.

New October records for Arctic warmth along with 500 mb blocking.

Second unprecedented slowdown in the October freeze-up as the Arctic easily surpasses previous records for October warmth and blocking. This is every bit impressive as the 2007 and 2012 melt seasons along with the record warmth this past winter and spring.

This will probably be the first melt year that is remembered more for the winter and spring than the summer.