Unfortunately those maps are rarely accurate for this area. Think of the boy who cried wolf... Once in a while they will show good conditions when we actually do, but there are dozens, if not hundreds of times when they will show that we should be having tropo, and there's nothing.
This map shows what is actually currently happening:
http://www.mountainlake.k12.mn.us/ham/aprs/path.cgi?map=na