Storm Coordination Message #4 – Damaging Wind/Heavy Rainfall/Minor Coastal Flooding Potential Thursday Night 12/24/20-Friday PM 12/25/20
Hello to all…
..Merry Christmas and Happy Holidays to all SKYWARN Spotters and Amateur Radio Operators. Due to the focus on the Christmas storm, the annual holiday message severe weather year in review will be delayed and sent out between Christmas Day and New Years Day. We appreciate everyone’s support during this storm and all the storms and severe weather events of the past year..
..Powerful storm system on track to hit the region late Christmas Eve night into Christmas Day Afternoon with damaging winds a significant potential threat along with heavy rainfall causing urban and poor drainage flooding and possibly river and stream flooding and the potential for minor coastal flooding at the time of high tide Friday Morning in south coastal Massachusetts and Rhode Island. There is even the potential for a fine line of strong to severe thunderstorms during the overnight hours Christmas Eve Night into Christmas Morning..
..A High Wind Warning remains in effect from Midnight Thursday Night through 4 PM Friday Afternoon for all of Rhode Island, Eastern Essex, Southeast Middlesex, Suffolk, Norfolk, Bristol, Plymouth, Barnstable, Dukes and Nantucket Counties of Massachusetts for sustained winds of 25-35 MPH, Gusts to 65 MPH and isolated to scattered higher gusts near any convection and across Southeast Coastal Massachusetts and South Coastal Rhode Island of 75 MPH. These winds will cause scattered to numerous pockets of tree and power line damage and power outages. The timeframe for highest winds is between 6 AM-12 PM Friday.
..A High Wind Warning remains in effect from Midnight Thursday Night through 12 PM Friday Afternoon for Northern Connecticut, Southern Worcester and Central Middlesex Counties of Massachusetts for sustained winds of 25-35 MPH, Gusts to 60 MPH and isolated to scattered higher gusts near any convection and in higher terrain locations. These winds will cause scattered to numerous pockets of tree and power line damage and power outages. The timeframe of strongest winds is between 5 AM-10 AM Friday..
..A Wind Advisory remains in effect from Midnight Thursday Night through 12 PM Friday Afternoon for Franklin, Hampden, Hampshire, Northern Worcester and Northern Middlesex Counties of Massachusetts for sustained winds of 10-25 MPH with gusts up to 50 MPH and isolated to scattered higher gusts near any convection and in higher terrain locations to 55 MPH. These winds will cause isolated to scattered pockets of tree and power line damage and power outages. The timeframe of strongest winds is between 5 AM-10 AM Friday..
..A Flood Watch remains in effect for the entire NWS Boston/Norton coverage area for heavy rainfall with widespread amounts of 1-3″ of rain with isolated pockets or a band of rainfall greater than 3″ in some part of the NWS Boston/Norton coverage area. This rainfall combined with snow melt may produce urban and poor drainage flooding and possibly river and stream flooding in portions of Southern New England..
..Minor coastal flooding could occur at the time of high tide Friday Morning in south coastal Massachusetts and Rhode Island and will be contingent on the maximum wind speeds coinciding with that high tide cycle and will be monitored..
..SKYWARN Self-Activation will be needed Christmas Eve night through Christmas Afternoon for the damaging wind potential along with the potential for urban and poor drainage flooding and minor coastal flooding in Southeast coastal New England. ARES/RACES groups should monitor this situation and seek advice from local leadership as we get closer to impacts from this storm system especially due to the damaging wind potential..
..Pictures and videos of storm damage and flooding can be sent to the WX1BOX Facebook and Twitter social media feeds, as a reply to this message or to the email address pics@nsradio.org with credit given to the SKYWARN Spotter/Amateur Radio Operator for the photos/videos..
A powerful storm system is on track to move through Southern New England late Christmas Eve night through Christmas Afternoon. The headlines depict the current thinking and there is no significant change since the last update. Key factors remain as follows:
1.) The wind impacts will likely be on the high-end and rival some of the past high impact wind events of the last 3 years and will bear close watching given the Christmas holiday. High Wind Warnings remain posted for Northern Connecticut, Rhode Island, South-Central and Eastern Massachusetts late Thursday Night into Friday Afternoon. Wind Advisories are posted for Western Massachusetts. While southerly wind events typically have a temperature inversion that keeps the strongest winds aloft, this storm event may allow the inversion to be broken between the heavy rainfall and any thunderstorms potentially allowing the strongest winds to reach the surface. In addition, winds at the upper levels of the atmosphere will be so powerful that even with 50-60% of those winds reaching the surface and now its expected that 70% of those winds could reach the surface, winds of high wind warning levels and potentially high-end high wind warning level winds would be possible.
2.) The increase in rainfall is expected to produce urban and poor drainage flooding and even some minor river and stream flooding between the heavy rainfall and the snow melt with more widespread 2-3″ rainfall expected with higher amounts greater than 3″ in isolated locations or in convective bands in the area. Flood Watches remain posted for the entire NWS Boston/Norton coverage area.
3.) Minor coastal flooding along South Coastal Massachusetts and Rhode Island will need to be monitored especially if the strongest winds occur near the time of high tide. At this time, the strongest winds are expected after the time of high tide.
SKYWARN Self-Activation will be needed Christmas Eve night through Christmas Afternoon for the damaging wind potential along with the potential for urban and poor drainage flooding and minor coastal flooding in Southeast coastal New England. ARES/RACES groups should monitor this situation and seek advice from local leadership as we get closer to impacts from this storm system.Pictures and videos of storm damage and flooding can be sent to the WX1BOX Facebook and Twitter social media feeds, as a reply to this message or to the email address pics@nsradio.org with credit given to the SKYWARN Spotter/Amateur Radio Operator for the photos/videos. This will be the last coordination message as we shift into operations mode unless a significant change to the situation occurs and time allows for an update. Below is the NWS Boston/Norton Area Forecast Discussion, High Wind Warning/Wind Advisory Statement, Flood Watch Statement, Enhanced Hazardous Weather Outlook, Rainfall Maps and Facebook Infographics on the Damaging Wind Potential:
NWS Boston/Norton Area Forecast Discussion:
https://kamala.cod.edu/ma/latest.fxus61.KBOX.html
NWS Boston/Norton High Wind Warning/Wind Advisory Statement:
https://kamala.cod.edu/ma/latest.wwus71.KBOX.html
NWS Boston/Norton Flood Watch Statement:
https://kamala.cod.edu/ma/latest.wgus61.KBOX.html
NWS Boston/Norton Enhanced Hazardous Weather Outlook:
https://www.weather.gov/box/ehwo
NWS Boston/Norton Rainfall Maps:
https://www.weather.gov/crh/pqpf?sid=box#tab-1
NWS Boston/Norton Facebook Infographics on Damaging Wind Potential:
https://www.facebook.com/NWSBoston/photos/pcb.3575744189186593/3575743735853305/
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
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