Now for some very quick and rough back of envelope calculations. This is quick and off the top of my head as I have to get out and will be busy for the rest of this weekend. I never got round to including snow depth into my simple model calculations of winter sea ice growth.
This is a measure of the amount of precipitation at the surface....
EDIT - posting early in the morning yesterday and in a rush I think this is probably wrong. As Ronan points out in the comments TPW should be a measure of the total column water vapour content and the following working out would be wrong. But yesterday when plotting the above graph it only let me do it for the surface, so I think I jumped to the conclusion that it was actually meaning surface precipitation.
So I am crossing out the following and replacing it with the following two implications as I see it.
1) Snow cover may have substantially reduced thickening in Jan and Feb. Snow insulates the ice from the atmosphere and reduces thickening. (PIOMAS models this effect and that data will be out soon).
2) The high TPW supports the idea that the warmth of the last two months is due to influx of warmer air from lower latitudes.
I felt rushed to get implication 1 posted as it could counter my previous post in which I calculated the impact of the Jan/Feb warmth on sea ice and found it relatively small. The effect of temperature and snow might not be small.
In the comments Kevin makes a very good point, that large open water areas (in the Atlantic) might be causing the high precipitable water figure. So I change the region to north of 70degN and only between 90degE and 210degE, which excludes the Atlantic.
Probably meaningless back of envelope comments follow - see comments.