A wintry mix of snow and rain is expected to impact Washington D.C. and its northern and western suburbs, with some accumulations forecasted. Schools may face delays as conditions worsen, particularly on Tuesday morning. The National Weather Service has issued advisories for several counties including Loudoun, Fauquier, and Culpeper, indicating slippery roads and travel impacts as a significant cold front moves through the region. Residents are advised to brace for a chilly December, with a mix of winter weather patterns likely to continue in the coming days.