Wouldn't a data point that's 8 SD below the mean actually be a 16 sigma event? If it's a normal distribution, the odds of seeing an occurrence 8 below should be the same of seeing one that's 8 above, for a total of 16 sigma. I'm not a science guy, but I use statistics to model demand for capacity in medical facilities, and a lot of patient arrival and demand is described pretty well by a normal distribution. Every demand curve I've built for inpatient beds and emergency beds is almost always a normal distribution (the range of census levels is contained within +/- 3 SD from the mean). In 20 years, I've never seen a hospital that had a range of 8 SD, and that includes some really small hospitals (which have bigger swings). Also, if I'm not mistaken, that's why the management tool 6 sigma is called 6 sigma. Every event would be expected to fall within + or - 3 sigma from the mean, for a total range of 6. So, if we are off by 8, that's actually a 16 sigma event, which is even scarier than an 8. It's like an amplifier that goes to 11, but even more insane.

Neven, Thank you so much for what you have done. Your even-keel and thoughtfulness have always set you and your blog apart, and are very much appreciated. Good luck with the house, educational efforts, and at achieving the balance you are looking for. Best wishes, Scott

Welcome back, Neven. You've been missed. Interesting times up north, indeed. Jim Pettit's graphs also just updated, with the Sea Ice Area maximum/minimum bar chart a fascinating read, as well as the line graph that overlays past years' melt as if they started at today's extent. If this year continues as 2012 did, we set a huge record, but nowhere near ice free...about 2MM square kms remain. If melting proceeds from here at the pace it did in 2007, we also set a new record, but not by much. No other year generates a record. That said, there's a lot of warmth projected over the next week, and a lot of dark water (more than ever before at this early date) absorbing the now prevalent sunlight. Thank you again for providing us with this amazing set of resources.

And the day after Robert Scribbler's post went up, the University of Bremen map looks like something straight out of June. Huge cracks in green and blue are everywhere, apparent melt north and east of Svalbard, Nares Strait has a huge pool of open water, Hudson's Bay is opening up, the CAA has pockets of melt and open water. Amazing. I know that map can shift day by day, but many of these features have been visible for several days now. I fear we are in for an interesting summer.

Neven, here in Minnesota we have a saying that is of little value and always applicable: It could be worse. At least it wasn't a sewer line that broke. Good luck with the cleanup.

Re: Explosive growth If you look at the map, it all comes pretty clear what happened. That obviously can't be right.

Gergyl, We have seen a similar change here in Minnesota. March has historically been our snowiest month. Now it's January. The theory is that January has warmed enough to now allow for bigger storms (warmer air holding more water vapor) while March has warmed so much that a lot of its snow is now falling as rain.

A-Team, I'm confused by the ice surface temperature information in your last post. How can the ice surface temperature be 12.8 or 15.9 degrees C? Is that Farenheit? Or am I missing something. I wish my first comment was a little more enlightening, but as a somewhat mathematically and scientifically literate lay-citizen, I figure I'm better off reading and asking simple questions than opening my mouth further and removing all doubt as to my ignorance. Thank you, Neven for this blog. I appreciate what you and everyone else here does.