I have been very successful using this link as well as Google Earth....

http://ndis.nrel.colostate.edu/maps/

You said that you had been researching DOW's page and maybe this one. I say "forget statistics" and look for Summer areas with lots of "lines' and go there. Winter areas are generally after the third season.

For example, look at areas 86 and 861 West of Walsenburg. There are some "HOT" spots there.