Winter Weather Update

****WINTER STORM WARNING FOR GREEN, ROCK AND WALWORTH COUNTIES FROM 3AM SUNDAY TO 6PM MONDAY****

****WINTER STORM WARNING FOR WINNEBAGO, BOONE AND MCHENRY COUNTIES FROM 3AM SUNDAY UNTIL 3PM SUNDAY AFTERNOON****

****WINTER WEATHER ADVISORY FOR OGLE AND DEKALB COUNTIES FROM 3AM SUNDAY UNTIL NOON****

****WINTER WEATHER ADVISORY FOR STEPHENSON, JO DAVIESS AND CARROLL COUNTIES FROM MIDNIGHT TONIGHT UNTIL 9AM SUNDAY****

As an area of low pressure begins to move closer to the region tonight, warmer air aloft will run over cooler air at the surface.  This will cause a mix of snow and sleet later tonight with accumulations likely.  As the warmer air continues to move in freezing rain will be likely by early Sunday morning with accumulations possibly reaching a tenth to a quarter of inch.  Further north into Wisconsin periods of heavy snow/sleet will be possible as temperatures will likely remain cooler; accumulations could range between 3"-6" with locally higher amounts.  As of now temperatures are expected to rise Sunday afternoon above freezing which should change the freezing rain over to just rain.  However, if temperatures do not warm the freezing rain will continue with significant ice accumulations possible. 

As the low pressure system continues to move through northern Illinois Sunday night a change over back to snow/sleet/freezing rain will be possible with additional accululations by Monday morning.  Travel Sunday may become difficult, if not dangerous, and conditions will be monitored very closely this evening and overnight.