I brought a litre or so of boiling water to make it easier to unstuck the snow pusher without breaking it.
The ice you're seeing is the result of snowmelt from the roof freezing again when not exposed to the sun. The air temperature is close to zero now and it is snowing. We're going to need the snowpusher probably tomorrow. The downpipe coming from the rain gutter/eavestrough/eaves channel is frozen shut. It is too late to install heating cables this spring but I'm definitely doing it before next winter. New snow is accumulating onto the roof.