Western Nevada County’s economy seems to be on a slight upturn, but whether the uptick is simply a sign of the shopping season or an actual indicator of improvement remains to be seen. Grass Valley’s downtown stores are indicating as much as a 30 percent spike in sales, said Julia Jordan, executive director of the Grass Valley Downtown Association. “I think it’s because the economy is on the rise, and a lot more people are shopping locally and supporting local businesses rather than big corporations,” Jordan said. “It’s nice that people are supporting small businesses that support our nonprofits and …