bluewave

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.

Statistical tie for 2nd place with 2007 on NSIDC. http://nsidc.org/arcticseaicenews/ Arctic sea ice appears to have reached its seasonal minimum extent for 2016 on September 10. A relatively rapid loss of sea ice in the first ten days of September has pushed the ice extent to a statistical tie with 2007 for the second lowest in the satellite record. September’s low extent followed a summer characterized by conditions generally unfavorable for sea ice loss. That September ice extent nevertheless fell to second lowest in the satellite record is hence surprising. Averaged for July through August, air temperatures at the 925 hPa level (about 2,500 feet above sea level) were 0.5 to 2 degrees Celsius (1 to 4 degrees Fahrenheit) below the 1981 to 2010 long-term average over much of the central Arctic Ocean, and near average to slightly higher than average near the North American and easternmost Siberian coasts. Reflecting the stormy conditions, sea level pressures were much lower than average in the central Arctic during these months. Why did extent fall to a tie for second lowest with 2007? The 2016 Arctic melt season started with arecord low maximum extent in March, and sea ice was measured at record low monthly extents well into June. Computer models of ice thickness, and maps of sea ice age both indicated a much thinner ice pack at the end of winter. Statistically, there is little relationship between May and September sea ice extents after removing the long-term trend, indicating the strong role of summer weather patterns in controlling sea ice loss. However, the initial ice thickness may play a significant role. As noted in our mid-August post, the upper ocean was quite warm this summer and ocean-driven melting is important during late summer. The science community will be examining these issues in more detail in coming months.

James Overland has a nice presentation on the record winter warmth in the Arctic this year which set the stage for the record low sea ice extent levels that were experienced during May. The more favorable polar vortex pattern for sea ice this summer prevented this from being the year which beat 2012.

Took one of the strongest summer polar vortex patterns over the Arctic of the 2000's to prevent this year from equaling or surpassing 2012. The most dramatic pattern change that you will ever see there following the strongest blocking pattern on record from Jan-May.

We'll see if we can keep the new record every 5 years going for 2017 with the previous records set in 2007 and 2012.

NSIDC moves into second place ahead of 2007 but well behind 2012. That dramatic dipole reversal in June prevented us from equaling or surpassing the 2012 record minimum. Impressive temperature spike at the pole with the steeper losses the last few days.

New record sea ice minimums seem to take longer to achieve than most people expect. I can remember the articles calling for an ice free Arctic by 2013 after the record low set in 2007. That record held on for 5 more seasons... longer than it was thought at the time. And after the record was finally broken in 2012, it is still holding on 4 years later despite renewed calls by some for an ice free Arctic by 2015 or 2016. So it will be interesting to see how long it actually takes to get to 1 million sq km or lower on NSIDC. Then the discussion would probably go to how long to zero. That may take a while due to compaction of the remaining sea ice up against the Canadian Archipelago and Greenland.

It's as extreme a pattern reversal that you are going to see from the winter and spring record warmth to cooler summer. That PV was so strong that the Pacific sector North of Alaska to near Siberia was actually colder than 2013 was.

It took the strongest summer Arctic polar vortex since 1996 for the slowest June into late August melt season since 2007 on NSIDC. The polar vortex was actually stronger than we saw in 2013.

This is officially the slowest melt season from June 21st to August 21st on NSIDC going back to 2007. The only reason we are challenging 2nd or 3rd place is due to the record warmth and dipole pattern from the winter into spring. The 2012 record low will last at least 5 years just like the 2007 record low did. NSIDC 6/1-8/21 loss since 2007 2016...6005 2015...6328 2014...6369 2013...6599 2012...7944 2011...6735 2010...6247 2009...6451 2008...6585 2007...7156

The 2012 record is safe no matter how much of an impact this storm has due to the reversal of the pattern in June. We would have had a good shot at at least rivaling the 2012 finish had that dipole persisted into June or July. https://nsidc.org/arcticseaicenews/ While there are still three to four weeks to go in the melt season, a new record low this September is highly unlikely. A simple projection method developed by Walt Meier at the NASA Goddard Space Flight Center uses daily ice loss rates from previous years to estimate possible trajectories of ice extent through the rest of the melt season. This approach yields a range of minimum values based on how sea ice loss progressed in previous years. By selecting from an average of multiple years, or using loss rates from a specific previous year, the method yields an estimate of the likely range of the minimum sea ice extent. As of August 14, using daily ice loss rates based on the 2006 to 2015 average yields an average projected 2016 minimum extent of 4.33 million square kilometers (1.67 million square miles). Using the slowest (recent) August to September decline, which occurred in 2006, yields a 2016 minimum of 4.76 million square kilometers (1.84 million square miles). Using the fastest rate of decline, from 2012, yields a 2016 minimum extent of 4.06 million square kilometers (1.57 million square miles). These two years bracket a reasonable range of expected 2016 minima. It is possible that this year will have decline rates that fall outside the range of previous years. However, this approach indicates that it is very unlikely that 2016 will have a minimum below 2012’s value of 3.39 million square kilometers (1.31 million square miles). A projection from August 1 was submitted to the Sea Ice Outlook.

Interesting that the summer 500 mb pattern went to the CCSM4 long range forecast twice since 2013. Here's the presentation that offers theories why this may be the case: https://ams.confex.com/ams/94Annual/webprogram/Paper235210.html

Slowest loss of sea ice on NSIDC going back to 2007 from June 1st to August 9th. This has to be the most dramatic reversal from a record warm winter and spring dipole pattern to summer polar vortex pattern on record. The summer dipole pattern that dominated the 2007-2012 era has been replaced by more of a polar vortex pattern since then with the exception of last July. We really need that type of a pattern to beat 2012 and make a run on the first ice free minimum. NSIDC sea ice losses from June 1st to August 9th since 2007: 2016...5137 2015...5442 2014...5538 2013...5629 2012...6914 2011...5921 2010...5660 2009...5645 2008...5708 2007...6614