Much of the South was forecast to see temperatures drop 30 to 45 degrees in a 24-hour period thanks to yet another arctic cold front, according to the latest forecasts. Some locations may even see their coldest temperatures ever recorded so late in the season, including Nashville and Louisville, Kentucky, where temperatures may drop into the single digits. A wintry mix of precipitation was already falling Wednesday night in Memphis, where a sheet of ice coated the roads, making driving especially hazardous. Mississippi counties were advised to open shelters powered by generators to give residents an option beyond cold, dark homes in the event of power outages. The Office of Personnel Management says non-emergency personnel in and around Washington are granted excused absences for the day. The D.C.