While parts of the country have seen heavy winds and tornadoes, St. Clair County is under a winter weather advisory until 10:00 a.m. Thursday, December 27. Hazardous weather is in the forecast, with snow expected to develop late this afternoon.   This snow will become moderate to briefly heavy at times through the evening hours, tapering off in intensity and coverage after midnight.   Total snowfall accumulations of 3 to 6 inches.  Brisk northeast winds of 15 to 25 mph will also cause blowing and drifting of the snow… along with reduced visibilities of a half mile or less.   Snow and blowing snow may result in hazardous Post Holiday travel conditions.  Authorities are advising motorists and travelers to keep an eye on the weather and be prepared for slippery roads and limited visibilities… and use caution while driving.   They say:  Prepare… plan… and stay informed. Visit   http://go.USA.Gov/rr8