I suspect the Spring trend is due to increased tilling by farmers to plough in snow. That generates a UHIE-like local warming meaning they can plant earlier.
I haven’t updated it for a while but the snow anomaly data is fun in that there’s been zero net trend for about 25 years. It’s also easy to read off a sat pic, so no need for complex adjustment algorithms. So the rising temperatures in even the UAH dataset aren’t moving the snow line northwards at all. Which begs the question whether the temperature dataset trends are real, since snow melts at 0 C irrespective of “adjustments”.
sunshine hours 
Reblogged this on Climate Collections.
I suspect the Spring trend is due to increased tilling by farmers to plough in snow. That generates a UHIE-like local warming meaning they can plant earlier.
I haven’t updated it for a while but the snow anomaly data is fun in that there’s been zero net trend for about 25 years. It’s also easy to read off a sat pic, so no need for complex adjustment algorithms. So the rising temperatures in even the UAH dataset aren’t moving the snow line northwards at all. Which begs the question whether the temperature dataset trends are real, since snow melts at 0 C irrespective of “adjustments”.