From the National Weather Service:
Special Weather Statement National Weather Service Boston/Norton MA 520 AM EDT Tue May 15 2018 MAZ020>024-RIZ004>008-151200- Southern Bristol MA-Southern Plymouth MA-Barnstable MA-Dukes MA- Nantucket MA-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, East Greenwich, Warwick, West Warwick, Bristol, Narragansett, Westerly, Newport, and New Shoreham 520 AM EDT Tue May 15 2018 ...PATCHY DENSE FOG WILL IMPACT THE MORNING COMMUTE... Patchy fog, locally dense in spots has developed across portions of the south coast. Visibilities have dropped to one quarter mile or less in some locations. Areas of poor visibility will improve after 8 AM as the fog lifts. Motorists should be prepared to encounter reduced visibilities in spots and should allow for increased braking distance between vehicles.