(UPDATED) WEATHER ADVISORY: Nor'Easter, Polar Vortex Bear Down On Merrimack Valley
Jan 02, 2018 05:54PM
● By Bill Gilman
It appears that 2018 will not be getting off to a quiet start.
The National Weather Service has issued a Winter Storm Watch, effective from Thursday, Jan. 4, at 1 a.m. though Friday, Jan. 5, at 1 a.m.
The latest forecast model calls for the Merrimack Valley to be hit with 8-12 inches of snow. But precipitation is just part of the problem. High winds, 25 to 35 mph, with gusts as high as 60 mph will create near-blizzard conditions.
And once the snow stops, a so-called "polar vortex" is expected to hit the region over the weekend, with temperatures dropping well below zero and a crippling windchill.
The Massachusetts Emergency Management Agency (MEMA) has released the following statement and information:
The National Weather Service (NWS) is forecasting a strong coastal storm on Thursday that will bring accumulating snow across the entire state, with the eastern half of the state seeing the greatest amounts. Strong and possibly damaging winds are also expected, with the greatest threat along the coast, including the Cape and Islands. Starting on Friday, bitterly cold weather will return and persist into the weekend.
Forecast for Thursday:
Snow will overspread the region starting early Thursday morning (between 4 AM and 8 AM) and last through the day before ending sometime Thursday evening (between 5 PM and 10 PM). Snowfall rates could be as much as 1-2” per hour.
In southeastern Massachusetts and the Cape and Islands, precipitation may start as rain but will transition to snow by Thursday afternoon as temperatures drop. A flash freeze is possible in this area. The precise location of the rain/snow line is still uncertain; it likely will fall somewhere south of the Boston to Providence line, and north of the Cape Cod Canal. There likely will be an area of heavy wet snow just to the north of the rain/snow line. The potential for power outages is higher in areas that receive heavy wet snow.
All of the state will see accumulating snow, with the greatest amounts in eastern and central Massachusetts, which could receive 8-12” of snow. The Cape and Islands is expected to receive 4-8” of snow, while western Massachusetts could see 3-6” of snow.
Wind gusts will increase Thursday morning and last into the evening. Interior Massachusetts could see 40-50 MPH gusts, with 50-65 MPH gusts near the coast and up to 70 MPH gusts on the Cape and Islands.
Thursday’s midday high tide is an astronomical high tide. Combined with the 1.5 to 2 feet of storm surge forecast, this tide could result in minor to moderate coastal flooding, especially on north and east facing beaches.
The major areas of uncertainty in the forecast at this point are (i) how far west the heaviest snowfall totals occur (if the storm tracks further west than currently forecast, central and western MA could also see up to 12” of snow), and (ii) the exact location of the rain/snow line in southeastern Massachusetts.
Forecast for Friday/Saturday:
Bitterly cold weather will return Friday and Saturday. Daytime highs will hover around 0 degrees, while overnight lows could reach 10-20 degrees below zero.
Wind chills could be as low as 15-35 degrees below zero, particularly on Friday night when wind gusts are expected to be 35-40 mph over much of Massachusetts.
Impacts associated with Thursday’s storm:
Snowfall combined with strong winds will result in poor visibility and difficult travel conditions throughout Massachusetts on Thursday. Both morning and evening commutes are forecast to be impacted. Near-blizzard conditions are possible in eastern Massachusetts and travel in this area could become difficult to impossible.
A flash freeze is possible Thursday afternoon or evening to the south of the rain/snow line as rain transitions to snow in southeastern Massachusetts, resulting in icy conditions on roads and sidewalks.
Strong wind gusts could cause tree damage and scattered power outages, especially on the Cape and Islands.
Minor to moderate coastal impacts are forecast from Boston northward and generally moderate coastal impacts for much of the coastline south of Boston. This may translate to fairly widespread flooding of vulnerable shore roads and basements. A few low spots might receive a little over 3 feet of inundation. Waves on top of the high water level may cause scattered damage to access stairs, docks, beach parking lots, decks/porches near the surf zone, and the like. Chunks of sea ice could also exacerbate scattered shoreline damage.
Impacts associated with cold weather Friday/Saturday:
Potentially life-threatening wind chill temperatures
Frostbite and hypothermia possible for those without proper protection from the cold. Frostbite can occur in as little as 30 minutes for unprotected skin.
Possible increase in fires from unsafe/improper use of alternative heating sources or people trying to thaw frozen pipes with blowtorches or similar devices
Possible increase in incidents of carbon monoxide poisoning from unsafe/improper use of alternative heating sources
Possible vehicle failure
Possible water main breaks and pipe bursts