A certain post-haste project has arisen, and I would like to put this question to the collective mind of GIS.SE for ideas and references. The long and short of this research is trying to find roads that lie within geographic areas that fit a given climatic profile. In this case, I need to find areas with relatively cold falls, winters, and springs that get snow. These places may not have a lot of snowfall on an annual basis, but the snow persists for longer periods due to the colder weather patterns. Are there any websites that already collect similar data in a format ready for GIS analysis? If not, what should I look for when gathering data? There may not be a singly perfect answer for this question, but I mostly am seeking direction to refine my search appropriately. Time is short.