7:27AM
This is the first of several updates to come throughout the storm. This one is only an update for time period and shows no changes to the discussion or forecast. The next will be posted this afternoon. Everybody stay safe!
Blizzard Warning through 1PM Saturday for most areas except portions of north central MA and Nantucket Island. Winter Storm Warning for these locations.
A blizzard is defined as winds of 35 MPH winds or greater and visibility under 1/4 mile due to heavy falling and/or blowing snow for a period of 3 hours or more. These conditions will take place over a large portion of the region Friday night into Saturday.
Storm track: Northeastward from the waters south of New England to the waters east of New England between Friday morning and Saturday night, possibly stalling for a time.
Mixing: Yes some mixing with rain is still possible over the immediate coast and especially Cape Cod and the Islands, hence the slightly lower projected totals there. But even there by mid storm it will be all snow.
Wet or dry snow? Wetter where mixing occurs and on the immediate shoreline to start, dry and fluffy elsewhere, then becoming drier and fluffy all other areas during the storm.
Start time: Ocean-effect snow showers may reach eastern MA around or after midnight or in the early hours of Friday morning. Storm’s snow will start light during Friday morning then grow steadier and more moderate into the afternoon and moderate to heavy by late afternoon.
Peak time: All of Friday night and well into Saturday morning when snowfall rates of up to 2 and even 3 inches per hour may occur.
End time: It may take all day Saturday to taper off but all snow should be done by early evening except lingering ocean-effect snow showers possible over parts of Cape Cod.
Accumulation (inches): 4-8 Nantucket through Outer Cape, 8-16 Mid Cape & Martha’s Vineyard, 10-18 Upper Cape, 18-30 elsewhere with a few 30+ amounts possible. IMPORTANT not to focus on the top number in the range. The large range is to cover the fact that much of the snow will be dry and fluffy and there can be great variability due to local effects (elevation, ocean-enhancement, etc.). Also, blowing and drifting will be considerable and will assure that very few areas end up with level snowcover when this is over anyway.
Coastal flooding: 2 to 3 feet of storm surge flooding is possible especially on north-facing and east-facing shorelines at high tide times Friday night and Saturday morning. Some property and shore road damage is possible.
Wind: Starting out east to northeast and increasing to 10-30 MPH during the day Friday, shifting more northerly with time, 25-45 MPH inland and 35-55 MPH higher elevations and coast with gusts 45-55+ MPH inland and 55-75+ MPH higher elevations and coast.
Power outages: Isolated to scattered. Not expecting widespread ones because much of the snow will be dry and not stick to the trees and power lines. This may be less the case on parts of Cape Cod and the Islands which may have wetter snow longer. Leafless trees also lessen the chance of trees coming down.
Lightning & thunder: Not out of the question that some occurs during this storm. It can be fairly common with intense winter storms.
Updated forecast for southeastern New England…
TONIGHT: Becoming cloudy. Ocean-effect snow showers possible east coastal areas around or after midnight. Lows 15-25 northwest to southeast. Wind E 5-15 MPH.
FRIDAY: Overcast. Snow develops, light and spotty then light and steady morning, growing moderate to eventually heavier at times during the afternoon. Mix/rain possible immediate coast especially south of Boston and Cape Cod/Islands. Highs 25-35 northwest to southeast. Wind E to NE 10-30 MPH, strongest near the coast.
FRIDAY NIGHT: Stormy. Moderate to often heavy snow except mix/rain parts of Nantucket and Outer Cape eventually changing to snow. Blizzard/white-out conditions often occurring. Rapid snow accumulations except in mix/rain areas. Lows 15-25 northwest to southeast. Wind NE to N increasing to 25-35 MPH with gusts 45-55 MPH inland and 35-45 MPH with gusts 55-75 MPH coastal and higher elevation areas. Isolated higher wind gusts are possible in all areas.
SATURDAY: Overcast. Blizzard conditions including heavy falling, blowing, and drifting snow to start the day, with gradual lessening of this during the day. Additional significant snow accumulation (see above for numbers). Temperatures steady 15-25 northwest to southeast. Wind N to NW 25-35 MPH inland and 35-50 MPH coast with higher gusts in the morning, diminishing slightly in the afternoon.
SATURDAY NIGHT: Lingering snow showers Cape Cod otherwise clearing. Lows around 10. Wind NW 15-35 MPH diminishing overnight. Additional blowing and drifting snow.
SUNDAY: Sunny. Highs 30-35. Wind W 5-15 MPH.
MONDAY: Clouding over. PM light snow/mix/rain. Low 20. High 40.
TUESDAY: Partly sunny. Low 28. High 42.
WEDNESDAY: Partly sunny. PM rain showers. Low 33. High 44.
THURSDAY: Variably cloudy. Chance of snow showers. Low 23. High 37.