How many inches will it snow tomarrow night in chicago? 10 ptz?

everyone at school today was saying we're expecting up to 20 inches but i don't know if it's accurate. oh and my mom said it might be a half day because of sever weather!!! yaaaaayyy but um, yea i'll probably give 10 ptz if you have a source or something...(or you're the only one that answers....)