From the National Weather Service:
Special Weather Statement National Weather Service Boston/Norton MA 807 PM EST Tue Feb 18 2020 MAZ020>024-RIZ002>008-190500- Southern Bristol MA-Southern Plymouth MA-Barnstable MA-Dukes MA- Nantucket MA-Southeast Providence RI-Western Kent RI- Eastern Kent RI-Bristol RI-Washington RI-Newport RI- Block Island RI- Including the cities of Fall River, New Bedford, Mattapoisett, Chatham, Falmouth, Provincetown, Vineyard Haven, Nantucket, Providence, Coventry, West Greenwich, East Greenwich, Warwick, West Warwick, Bristol, Narragansett, Westerly, Newport, and New Shoreham 807 PM EST Tue Feb 18 2020 ...AREAS OF FOG WILL BE DENSE AT TIMES ALONG THE SOUTH COAST INCLUDING CAPE COD AND THE ISLANDS THROUGH THE EVENING... Areas of fog will be dense at times along the south coasts of Massachusetts and Rhode Island, including Cape Cod and the Islands this evening. Visibility will be reduced to one quarter of a mile at times. Motorists traveling through the evening should be prepared for rapidly changing visibility over short distances and drive with extra caution. Visibility will improve after midnight as drier air works in from the west.