Hi...I'm trying to understand more about snowpack analysis. The charts I'm interested in are produced by this centre, focussed on NE Italy and Austria: https://avalanche.report/bulletin/2019-01-02?lang=en
My specific question is what's the difference between the light blue and dark blue areas on the chart?
Here's an example: https://valanghe.report/blog/trentinovalanghe.blogspot.com/5677690958415598...
Thanks in advance!