According to the model sea ice volume hasn't been as low on May 31st as this year. It looks like we're seeing the same crash as in 2010 and 2011, but right now 2012 is 562 km3 lower than 2011, and 1262 km3 lower than 2010.
Here is Wipneus' version for which he calculated the "expected" 2012 values (dotted lines), based on the same date values of 1979-2011 and an exponential trend. A caveat from Wipneus: "Note that the (not indicated) statistical error bars are quite large."
The PIOMAS anomaly graph shows that the anomaly trend line has exited the 2 STD zone (here is last month's graph), which means volume is dropping faster than the 1979-2012 linear trend:
I have used my crude method of dividing PIOMAS volume numbers by Cryosphere Today area numbers to calculate the average thickness of the ice pack. Again, this is just an indication that allows us to compare with previous years:
Average thickness for May 31st (in m):
- 2005: 2.33
- 2006: 2.31
- 2007: 2.16
- 2008: 2.29
- 2009: 2.14
- 2010: 1.95
- 2011: 1.86
- 2012: 1.82