STOCKTON — As the months now turn into days and soon into hours, student organizers of the NorCal Science Festival are brimming with positivity.“Everybody is pretty excited about it,” said Kim Le, a junior at Tokay High School. “We’re hoping for it to go well and we know things will go well.”The daylong festival celebrating all things science, technology, engineering, art and mathematics returns on Saturday at Tokay High from 10 a.m.