The snow that blanketed Nevada County Tuesday left a positive effect on the scenery, but a negative effect on schools and drivers. Nevada Joint Union High School District released students at 12:30 p.m. to ensure the safety of students, said Marianne Cartan, NJUHSD superintendent. “The high school district always chooses to err on the side of caution, so we’re more conservative and will release early,” Cartan said. “Because we don’t know if (the snow) will or won’t (stop). We have students who live in high elevations, so they might be fine on Ridge Road, but they have to get home. …