When we get snow, the solar panels get covered. If it's a light snow, just a little sunlight melts that layer. But when it's a big snow, the sun gets through a little, heats the black panels and eventually there's a layer of water there and the snow slides off all at once. Temperatures above freezing can do that as well if the sun isn't out.

When it slides though, it sounds like an avalanche from inside the house. Or outside as well, for that matter. Once, in CT, we were outside clearing the sidewalk when it happened and came close to getting buried as 24 panels of snow came off the front of the house all at once.

This morning at 5:20 AM though was the first time I remember it happening overnight. It was sunny yesterday, so it got it prepped, I guess, such that when the temps rose overnight to be above freezing it let go on the top front roof panels....right over our bedroom. The rumble woke us up. Just had the 2nd a few minutes ago, I think from the back panels, or maybe the first didn't get all of the front.