Storm Coordination Message #3 – Late Friday Night 12/4/20-Sunday Morning 12/6/20 Coastal Storm Impacts

Hello to all…

..Significant coastal storm on track for impacts across Southern New England late Friday Night through early Sunday Morning. Uncertainty is higher than normal at this time due to high spread in model guidance despite being about 12-18 hours from the potentially significant coastal storm event but there is the potential for heavy rainfall at the coast, heavy rain changing to a heavy wet snow in portions of interior Southern New England along with strong to damaging winds in the coastal areas..
..A Winter Storm Warning is now in effect from 7 AM Saturday to 7 AM Sunday for Worcester and Northern Middlesex Counties of Massachusetts for 6-12″ of snow with isolated higher amounts and the highest snow amounts above 1000 foot elevation along with wind gusts to 45 MPH. The snow will be heavy and wet and coupled with the strong winds will result in scattered to numerous pockets of tree and wire damage and scattered to numerous power outages..
..A Winter Storm Watch remains in effect from Saturday Morning through Sunday Morning for Franklin, Hampshire, Hampden, Southeast Middlesex Counties of Massachusetts and Tolland and Windham Counties of Connecticut for 6″ or more of snow. The snow will have the potential to be heavy and wet and if it accumulates 4″ or more along with the potential of wind gusts up to 45 MPH, there will be the potential for scattered to numerous pockets of tree and wire damage and scattered to numerous power outages..
..Northwest Rhode Island and other parts of Northern Connecticut and interior Eastern Massachusetts could also see accumulating snow depending on the track speed and intensity of this coastal storm..
..A High Wind Warning is now in effect from 1 PM Saturday Afternoon to Midnight Saturday Night for Eastern Plymouth County Massachusetts, Cape Cod and the Islands for sustained winds of 20-30 MPH with gusts up to 60 MPH and isolated higher gusts possible. Other areas of Eastern New England could see wind gusts up to 50 MPH with higher gusts and Wind Advisories could be needed in later updates. These winds will cause isolated to scattered pockets of tree and wire damage and isolated to scattered power outages..
..SKYWARN Self-Activation will monitor this storm throughout the duration of the event. It is noted that this storm is coinciding with SKYWARN Recognition Day (SRD) and the WX1BOX Amateur Radio team will make a best effort to continue to support this event per current plans with the understanding that storm operations will take precedence and an updated SRD message will be sent later this evening..

Models are depicting and on track for a significant storm to affect the Mid-Atlantic and New England late Friday Night through Sunday Morning. That being said there is larger than normal spread in the guidance in terms of track and intensity and where intensification occurs which will have significant impacts to the forecast. Key factors include:

1.) How the jet streams phase and does that occur close enough to Southern New England. Some of the reliable model guidance certainly depicts that to be close to Southern New England for significant impacts. At this time, the eastern trend has halted and has trended back a bit west along with pretty much all model guidance calling for significant impacts from this storm.
2.) The higher terrain areas will have the potential to experience the most snow. At this time, highest confidence is in the Winter Storm Warning area of Worcester through Northern Middlesex Counties of Massachusetts though the axis could shift a bit west or east depending on storm position and where the rapid intensification occurs. Other parts of the Winter Storm Watch area could see these heavier impacts and its a question of whether its western or eastern parts of the watch area. There is the potential for high snowfall rates of 2-3″ per hour and with the potential for heavy wet snow, there is an increased risk for numerous trees and wires down and numerous power outages wherever this band sets up and where snow is 4″ or more in the area. At this time, Worcester and Northern Middlesex Counties of Massachusetts are at the highest risk of this potential but other parts of the Winter Storm Watch area could see this potential.
3.) The intensity of the winds will be determined by the track, speed and intensity of the storm system. Currently inland wind gusts are expected to be 40-50 MPH with isolated higher gusts and wind gusts of 50-60 MPH with isolated higher wind gusts across coastal Southern New England. High Wind Warnings are now up for Cape Cod and the Islands and Eastern Plymouth County Massachusetts with Wind Advisories possible for other parts of Eastern New England.

SKYWARN Self-Activation will monitor this storm throughout the duration of the event. It is noted that this storm is coinciding with SKYWARN Recognition Day (SRD) and the WX1BOX Amateur Radio team will make a best effort to continue to support this event per current plans with the understanding that storm operations will take precedence and an updated SRD message will be sent later this evening. Another coordination message will be posted by 1030 AM Saturday Morning. Below is the NWS Boston/Norton Winter Storm Warning/Watch Statement, High Wind Warning Statement, Area Forecast Discussion, Enhanced Hazardous Weather Outlook, Snowfall and Rainfall Maps:

NWS Boston/Norton Winter Storm Warning/Watch Statement:
https://kamala.cod.edu/ma/latest.wwus41.KBOX.html

NWS Boston/Norton High Wind Warning Statement:
https://kamala.cod.edu/ma/latest.wwus71.KBOX.html

NWS Boston/Norton Area Forecast Discussion:
https://kamala.cod.edu/ma/latest.fxus61.KBOX.html

NWS Boston/Norton Enhanced Hazardous Weather Outlook:
https://www.weather.gov/box/ehwo

NWS Boston/Norton Snowfall Maps:
https://www.weather.gov/box/winter

NWS Boston/Norton Rainfall Maps:
https://www.weather.gov/crh/pqpf?sid=box

Respectfully Submitted,

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: rmacedo@rcn.com
http://ares.ema.arrl.org
http://www.wx1box.org
Like us on Facebook – http://www.facebook.com/wx1box
Follow us on Twitter – http://twitter.com/wx1box