A few days of strongish melting makes quite a difference.
On June 1st 2017 JAXA sea ice extent was 733,000 km2 greater than 2016, and average daily melting (from April 1) was 22% less than 2016.
As at 21st June that difference is down to 157,000 km2 and the average daily melting rate (again from April 1 ) is now only 2% less than 2016.
If melting from now to minimum is at the average of the previous 10 years, the 2017 minimum would tie with 2016 as 2nd lowest at 4.02 million km2. This is a significant change from earlier this month when a 5% above average melt would have been required.
However, to be a new record low (i.e. less than 2102) still requires remaining melting to be 15% above the 10 year average.
This is summarised in the little table below:-
As At June 21 Melt required As % av Resulting Minimum
For 2016 Result 5,711,402 100.0% 4,017,264
For 2012 Result 6,551,211 114.8% 3,177,455
For 2007 Result 5,662,927 99.2% 4,065,739
Average 7-16 melt 5,708,577 4,020,089
The data illustrates how extraordinary the 2012 melting season was. (A similar story can be told on Greenland's melting in 2012).
There are about 85 days of the melting season left, of which perhaps 75 are significant in an average year. Although the Arctic temperatures are not yet at maximum, peak insolation day was yesterday.
If all other things are equal, a 2nd lowest minimum despite not particularly favourable climatic conditions seems eminently possible. However, not all other things are or will be equal. When will the thickness of the ice in the CAB reduce to below the point of no return?