Today’s wind chill advisory by the National Weather Service is in effect until 11 a.m. for South Jersey. Wind chills dipped below minus 20 degrees in some areas this morning. The weather service warns of possible frostbite, hypothermia and frozen pipes. Vineland public schools will open two hours late today because of the cold weather. Teachers and staff are on a 90-minute delay. This morning at Atlantic City International Airport the temperature fell to 1 degree, just above the low record of zero.