My original post was incorrect. I originally compared April 18 vs. the second April 16 graph, not the first one. The new NSIDC graph lines up correctly with the old April 16 version, but the time stamp is two days later. My apologies for the error.
NSIDC says they have fixed the earlier error, but today’s graph still appears incorrect. The image above overlays the April 18 graph on the original April 16 graph, with 2012 data normalized. There is still a shift in the climatology relative to the 2012 data. This should not be happening.
Pixel counting the extent map shows 12% more area of excess ice (green) than missing ice (red.) So we should expect to see NSIDC cross above the mean in two days.
My pixel counts agree with Cryosphere Today numbers, which show more excess ice in the Bering Sea, than missing ice in the Barents Sea.