Storm Coordination Message #4 – Wednesday Night 12/16/20-Thursday Afternoon 12/17/20 Major Winter Storm Potential
Hello to all…
..A significant major winter storm is on track for much of Southern New England. The major winter storm will have the potential to bring heavy snow, the potential for whiteout and near blizzard conditions, strong wind gusts at the coast of up to 50-60 MPH, 40-45 MPH with isolated higher wind gust inland and the potential for minor to low-end moderate coastal flooding at the time of high tide Thursday..
..A Winter Storm Warning remains in effect from 7 PM Wednesday Night through 1 PM Thursday for Northern Connecticut, Providence and Western Kent Counties of Rhode Island and Franklin, Hampshire, Hampden, Worcester, Norfolk, Essex, Middlesex and Suffolk Counties of Massachusetts for 10-17″ of snow with isolated higher amounts possible and wind gusts up to 40-45 MPH inland and 45-50 MPH at the coast. The winds and heavy snowfall may create a period of whiteout and near blizzard conditions..
..A Winter Storm Warning is now in effect from 7 PM Wednesday Night through 1 PM Thursday for the remainder of Rhode Island, Bristol, Plymouth and Barnstable Counties of Massachusetts for 6-12″ of snow and isolated higher amounts possible and wind gusts of up to 45 MPH inland, 50-55 MPH with isolated higher gusts in East and South Coastal Massachusetts and Rhode Island and 55-60 MPH on Cape Cod with isolated higher gusts. These winds along with the snow possibly being heavy and wet especially at the coast could result in isolated to scattered pockets of tree and wire damage and power outages..
..A Winter Weather Advisory is now in effect from 7 PM Wednesday Night through 1 PM Thursday for Dukes County (Marthas Vineyard) for 3-6″ of snow and wind gusts to 60 MPH. The winds and the wet snow may cause isolated to scattered pockets of tree and wire damage and power outages..
..A High Wind Warning is now in effect from 10 PM Wednesday Evening through 10 AM Thursday Morning for Block Island RI, Marthas Vineyard and Nantucket for sustained winds of 30-40 MPH with gusts to 60 MPH and isolated higher gusts possible. These winds and any snow particularly on Martha’s Vineyard may result in isolated pockets of tree and wire damage and isolated power outages..
..A Coastal Flood Advisory is now in effect from 10 AM to 4 PM Thursday for East Coastal Massachusetts, Cape Cod, Marthas Vineyard and Nantucket for minor shore road flooding of coastal roads and the time of the Thursday high tide cycle..
..SKYWARN Self-Activation with Amateur Radio Call-Up Nets likely late Wednesday Night through Thursday Afternoon. Some of the heaviest snow is expected overnight through the Thursday Morning commute with high snowfall rates. Any spotter reports during overnight hours as well as throughout the storm on snow accumulation, snow/wind damage and any precip changeover in Southeast New England will be critical to help forecasts throughout the storm..
A potentially significant and major winter storm is now expected across all of Southern New England with weather models now largely aligned on outcomes. The headlines depict the current thinking with Winter Storm Warnings now in place across much of Southern New England except for the islands. Winds look a bit stronger prompting High Wind Warnings for the islands with the wind threat for other areas. Key factors include:
1.) The cutoff of heavy snow is now expected to be north of the NWS Norton coverage area and hence the Winter Storm Warnings and those warnings pushed northward up to the New Hampshire border.
2.) The southern parts of the area from Southern Rhode Island through Southeast Massachusetts possibly as far north as Boston, Cape Cod and Marthas Vineyard could have a mix or changeover to sleet and rain for a few hours before a change back to snow and a flash freeze causing rapid icing conditions. Areas in Southeast New England are now expected to see 6-12″ of snow with the wide variance due to any mixing that may take place. The question will be how much snow occurs in a front-end thump of heavy precipitation before the mix or changeover and whether the mix or changeover occurs. This looks most likely for the Outer Cape and Marthas Vineyard but could extend to other parts of Southeast coastal New England. In addition, this could mean a wetter snow for this area and the tree and power line damage potential will need monitoring between the wet snow and strong wind gusts to 45-60 MPH.
3.) Widespread 10″-17″ of snow could occur across Northern Connecticut, Northwest Rhode Island and interior Massachusetts along, north and west of I-95. Higher amounts greater than 17″ are possible in some parts of this area. The strong winds and heavy snowfall rates could cause whiteout and near blizzard conditions.
4.) The low pressure system will not be particularly strong but does look a bit stronger than earlier modeled and the pressure gradient of winds between low pressure to the south and high pressure to the north coupled with high astronomical tides will result in minor to possibly low-end moderate coastal flooding depending on the strength of the winds at the time of high tide. A coastal flood advisory remains in effect for East Coastal Massachusetts, Cape Cod and Marthas Vineyard to cover this potential.
5.) Wind gusts of 45-60 MPH are expected along Southeast coastal New England. This is covered in Winter Storm Warnings headlines for most areas and a High Wind Warning is in effect for the islands for the wind gust potential to 60 MPH. This could result in isolated tree and power line damage and isolated power outages. If the system were to be stronger than currently modeled, the potential for stronger wind gusts would increase.
SKYWARN Self-Activation with Amateur Radio Call-Up Nets likely late Wednesday Night through Thursday Afternoon. Some of the heaviest snow is expected overnight through the Thursday Morning commute with high snowfall rates. Any spotter reports during overnight hours as well as throughout the storm on snow accumulation, snow/wind damage and any precip changeover in Southeast New England will be critical to help forecasts throughout the storm. This will be the last coordination message unless a significant update to the situation occurs and time allows for an update as we shift into operations mode. Below is the NWS Boston/Norton Area Forecast Discussion, Winter Storm Warning/Winter Weather Advisory Statement, High Wind Warning statement, Coastal Flood Advisory Statement, Enhanced Hazardous Weather Outlook and Snowfall Maps:
NWS Boston/Norton Area Forecast Discussion:
NWS Boston/Norton Winter Storm Warning/Watch Statement:
NWS Boston/Norton High Wind Warning Statement:
NWS Boston/Norton Coastal Flood Advisory Statement:
NWS Boston/Norton Enhanced Hazardous Weather Outlook:
NWS Boston/Norton Snowfall Maps:
Robert Macedo (KD1CY)
ARES SKYWARN Coordinator
Eastern Massachusetts ARES Section Emergency Coordinator
Home Phone #: (508) 994-1875 (After 6 PM)
Home/Data #: (508) 997-4503 (After 6 PM)
Work Phone #: 508-346-2929 (8 AM-5 PM)
Email Address: email@example.com
Like us on Facebook – http://www.facebook.com/wx1box
Follow us on Twitter – http://twitter.com/wx1box