From the National Weather Service:
URGENT - WINTER WEATHER MESSAGE National Weather Service Taunton MA 952 PM EST Thu Mar 9 2017 MAZ022>024-RIZ008-101100- /O.CON.KBOX.WS.W.0004.170310T0800Z-170310T2100Z/ Barnstable MA-Dukes MA-Nantucket MA-Block Island RI- Including the cities of Chatham, Falmouth, Provincetown, Vineyard Haven, Nantucket, and New Shoreham 952 PM EST Thu Mar 9 2017 ...WINTER STORM WARNING REMAINS IN EFFECT FROM 3 AM TO 4 PM EST FRIDAY... * LOCATIONS...Cape Cod, Nantucket, Marthas Vineyard and Block Island. * HAZARD TYPES...Heavy snow. * ACCUMULATIONS...Snow accumulation of 6 to 10 inches. * TIMING...Snow will develop after 4 AM, becoming heavy at times during the morning and into midday Friday. Snowfall rates of 1 to 2 inches per hour are possible at times. The snow will taper off mid afternoon Friday. * IMPACTS...Snow covered roads will make for hazardous travel conditions. * VISIBILITIES...One quarter mile or less at times. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Winter Storm Warning is issued when an average snowfall of 6 inches or more is expected within a 12 hour period, or for 8 inches or more in a 24 hour period. Travel will be slow at best on well treated surfaces, and quite difficult on untreated surfaces. Only travel in an emergency. If you must travel, keep an extra flashlight, food, and water in your vehicle in case of an emergency.