Storm Coordination Message #3 – Late Thursday Night 12/20/18-Late Friday Night 12/21/18 Heavy Rain/High Wind/Severe Weather Potential

Hello to all…

..Very strong and unusually warm storm system for December is on track to impact the region with the potential for very heavy rainfall and the potential for urban and poor drainage flooding to possibly even small river and stream flooding, strong to damaging winds and possibly even isolated strong to severe thunderstorms that will have the potential to bring stronger winds to the surface with the strong to severe thunderstorm potential highest in Southeast New England..
..A Flood Watch remains in effect for the entire NWS Boston/Norton coverage area from late Thursday Night through late Friday Night for at least 1-3″ of rain with higher amounts possible to likely and the potential for urban and poor drainage flooding to possibly small river and stream flooding..
..A High Wind Warning is now in effect for Cape Cod and the Islands from 7 AM-10 PM Friday for Cape Cod and the Islands for sustained winds of 25-35 MPH with gusts to 60 MPH. A Wind Advisory is now in effect from 6 AM-10 PM Friday for Essex, Southeast Middlesex, Suffolk, Norfolk, Bristol, Plymouth Counties of Massachusetts and all of Rhode Island except for Northwest Rhode Island for sustained winds of 25-35 MPH with gusts to 45-55 MPH. These winds will cause isolated to scattered pockets of tree and wire damage and isolated to scattered power outages..
..A Coastal Flood Advisory is now in effect from 4-9 PM Friday for South Coastal Massachusetts, Cape Cod and South Coastal Rhode Island for minor coastal flooding at the time of high tide on the most vulnerable shore roads in this area..
..SKYWARN Activation with Ops at NWS Boston/Norton will commence by around 7-8 AM Friday Morning lasting through Friday Evening..

An unusually strong and warm storm system for December is on track to impact the region late Thursday Night into late Friday Night. The headlines depict current thinking including converting the High Wind Watch to a High Wind Warning for Cape Cod and the Islands and the posting of a Wind Advisory for East Coastal and Southeast Massachusetts and all of Rhode Island except Northwest Rhode Island and the issuance of a Coastal Flood Advisory for the Friday Evening high tide cycle for South Coastal Massachusetts and Rhode Island including Cape Cod. Key factors for this storm system remains as follows:

1.) Rainfall amounts of 1-3″ are likely but its quite possible higher amounts of greater than 3″ could occur as it will be an unusually warm and moist atmosphere for December over the area. As amounts approach or exceed 3″ and depending on the aerial coverage of those rainfall amounts, the risk for flooding increases and this will be watched closely.
2.) There will be very strong winds aloft out of the south and southeast direction. Typically, these winds struggle to reach the surface however given the storm setup and particularly over Southeast New England where temperatures could potentially be as high as 60 degrees or possibly above 60 degrees, that could potentially allow these winds to mix to the surface more prevalently than normal. Also, any thunderstorm activity or heavy convective downpours would also be a mechanism to bring stronger winds down to the surface. These aspects will bear watching as we get closer to the storm event.
3.) While very unusual, we will have to monitor the potential for even isolated severe thunderstorms in this environment and even the very low possibility that an isolated waterspout or tornado could occur particularly in Southeast New England. The unusual warm, moist atmosphere, very strong wind fields aloft and the potential for low-level instability would make this possible with the key conditional component the low-level instability. This will bear close watching.
4.) Minor coastal flooding is now most likely during the Friday Evening high tide where a Coastal Flood Advisory has been posted.

SKYWARN Activation with Ops at NWS Boston/Norton will commence by around 7-8 AM Friday Morning lasting through Friday Evening. This will likely be the last coordination message for this storm event as we move into Amateur Radio Operations mode early Friday Morning unless a significant upgrade to the situation occurs and time allows for an update. Below is the NWS Boston/Norton Flood Watch Statement, High Wind Warning/Wind Advisory Statement, Coastal Flood Advisory Statement, Hazardous Weather Outlook, Enhanced Hazardous Weather Outlook and Facebook Infographics:

NWS Boston/Norton Flood Watch Statement:
https://kamala.cod.edu/ma/latest.wgus61.KBOX.html

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

NWS Boston/Norton Coastal Flood Advisory Statement:
https://kamala.cod.edu/ma/latest.whus41.KBOX.html

NWS Boston/Norton Hazardous Weather Outlook:
https://kamala.cod.edu/ma/latest.flus41.KBOX.html

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

NWS Boston/Norton Facebook Infographics:
https://www.facebook.com/NWSBoston/photos/pcb.2010425592385135/2010425475718480/?type=3&theater

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
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