National Weather Service say visibility about one-quarter mile.
DCZ001-MDZ003>006-011-013-014-503>508-VAZ025>031-036>040-050>054- 501-502-505>508-WVZ051>053-140500- /O.NEW.KLWX.FG.Y.0010.191213T2159Z-191214T0500Z/ District of Columbia-Washington-Frederick MD-Carroll- Northern Baltimore-Southern Baltimore-Prince Georges-Anne Arundel- Northwest Montgomery-Central and Southeast Montgomery- Northwest Howard-Central and Southeast Howard-Northwest Harford- Southeast Harford-Augusta-Rockingham-Shenandoah-Frederick VA-Page- Warren-Clarke-Nelson-Albemarle-Greene-Madison-Rappahannock-Orange- Culpeper-Prince William/Manassas/Manassas Park-Fairfax- Arlington/Falls Church/Alexandria-Northern Fauquier- Southern Fauquier-Western Loudoun-Eastern Loudoun- Northern Virginia Blue Ridge-Central Virginia Blue Ridge-Morgan- Berkeley-Jefferson- Including the cities of Washington, Hagerstown, Frederick, Ballenger Creek, Eldersburg, Westminster, Reisterstown, Cockeysville, Baltimore, Bowie, Suitland-Silver Hill, Clinton, College Park, Greenbelt, Laurel, Camp Springs, Glen Burnie, Annapolis, Severn, South Gate, Severna Park, Arnold, Odenton, Germantown, Damascus, Bethesda, Rockville, Gaithersburg, Silver Spring, Lisbon, Columbia, Ellicott City, Jarrettsville, Aberdeen, Staunton, Waynesboro, Stuarts Draft, Harrisonburg, Strasburg, Woodstock, Mount Jackson, New Market, Winchester, Luray, Shenandoah, Stanley, Front Royal, Berryville, Lovingston, Charlottesville, Stanardsville, Madison, Orange, Gordonsville, Culpeper, Dale City, Manassas, Woodbridge, Lake Ridge, Montclair, Reston, Herndon, Annandale, Centreville, Chantilly, McLean, Franconia, Arlington, Alexandria, Falls Church, Warrenton, Turnbull, Purcellville, Leesburg, Ashburn, Sterling, Big Meadows, Wintergreen, Paw Paw, Martinsburg, Charles Town, and Shepherdstown 459 PM EST Fri Dec 13 2019 ...DENSE FOG ADVISORY IN EFFECT UNTIL MIDNIGHT EST TONIGHT... * WHAT...Areas of dense fog with visibility around one-quarter mile. * WHERE...The Washington and Baltimore Metropolitan areas, central Maryland, northern Virginia, portions of central Virginia and eastern West Virginia. * WHEN...Until midnight EST tonight. * IMPACTS...Hazardous driving conditions due to low visibility. PRECAUTIONARY/PREPAREDNESS ACTIONS... If driving, slow down, use your headlights, and leave plenty of distance ahead of you. By The National Weather Service