* WHAT...Blowing and drifting snow reducing visibility to near zero in spots, mainly in open areas. * WHERE...Portions of central, east central, north central, and northeast Illinois and northwest Indiana. * WHEN...Until midnight CDT tonight. * IMPACTS...Plan on slippery road conditions. * ADDITIONAL DETAILS...Strong west northwesterly winds will continue to result in severe blowing and drifting snow in open areas this evening. Some locations may experience near white out conditions, mainly along north-south roadways, which may also become drifted over and snow covered.