Special Weather Statement issued February 11 at 8:19PM EST by NWS

…Areas of dense fog likely through midnight… Areas of dense fog will continue to develop across the Hudson and Mohawk River Valleys, eastern Catskills and Helderbergs, southern Vermont, the Berkshires, and Litchfield Hills through midnight. The visibility may drop to near or below one quarter of a mile at times in these areas.

Source: National Weather Service Alerts for Vermont