An interesting effort from NOAA as they share a process for mapping the approximate first day of snow
Colored dots indicate the date by which there’s a 50% chance at least 0.1” of snow will have accumulated, based on each location’s snowfall history from 1981-2010. Click the map for a larger version with more detailed categories. Map by NOAA Climate.gov, based on analysis of the US Climate Normals by Mike Squires, National Centers for Environmental Information.
Read full article HERE.