Get out and enjoy the warm weather in western Nevada County today - it may not last.While forecasters are calling for sunny, dry weather and temperatures in the upper 60s today, a cold front is expected to move into the Sierra Wednesday, according to the National Weather Service in Sacramento.Temperatures are expected to reach the low 60s Wednesday before giving way to clouds and temperatures in the mid-30s at night. Trace amounts of snow could fall down to 3,000 feet Thursday morning, and temperatures are expected to top out in the 40s that day, forecasters said.Cool, clear conditions are expected …