Purchase sidewalk salt also called calcium chloride from your local hardware or big box store.
Snow melt patterns on roof.
Gently toss the tied off pantyhose onto the edge of your roof to begin melting the snow.
I also see plenty of homes with uneven melt patterns across their roofs and this typically means that there is insulation missing in some of the rafter bays or quite likely an interior wall is coming up to the attic and has no air sealing to stop air from moving into the wall cavity from the house and up to the roof.
On frosty and snowy mornings melt patterns will become readily visible.
Because the snow is melting from a heat loss on your roof and not because of warming temperatures the melted snow can refreeze once it travels from your roof creating ice dams that appear as icicles on the eaves and gutters.
When snow begins to gradually melt off a roof vehicle or other outside structure you might occasionally see some odd patterns develop.
Winter storm central.
The patterns relate to attic insulation.
Place this vertically on your roof near the edge so it will melt a section of snow and ice creating an area where the water can leak off.
As you look at the patterns the mosaic of patterns will show which homes are more air tight and well insulated than others.
If your attic has little or no insulation the snow will disappear quickly.