Storm Coordination Message #5 – Major Winter Storm Potential Saturday Evening 1/19/19-Sunday Evening 1/20/19

Hello to all…

..Major winter storm expected and on track for much of Southern New England late Saturday Afternoon into Sunday Night. Model trends are shifting with the potential for more icing and less snow but further changes to the forecast will await all model guidance and those changes if needed will be made in the afternoon update..
..There will remain a period of heavy snow and significant icing both possible with snow and ice changing to heavy rain and strong winds along coastal areas and the heavy rain potentially now extending into parts of the Boston to Providence corridor then changing back to snow with a flash freeze before ending. The potential for minor to moderate coastal flooding at the time of high tide as we get into the Sunday Morning high tide cycle in East and South Coastal Massachusetts..
..A Winter Storm Warning remains in effect from 4 PM Saturday Afternoon to 7 PM Sunday Evening for Franklin, Northern Worcester, Middlesex, Essex and Hampshire Counties of Massachusetts for 7-14″ of snow with isolated higher amounts from the route 2 corridor north and west and wind gusts of 35-40 MPH. It is noted that the next update could bring less snowfall but more ice for parts of this warning area..
..A Winter Storm Warning is now in effect from 4 PM Saturday Afternoon to 7 PM Sunday Evening for Hampden and Southern Worcester Counties of Massachusetts for 4-8″ of snow and one-tenth to four-tenths of an inch of ice and wind gusts to 35-40 MPH. It is noted that the next update could bring less snowfall but more ice for parts of this warning area..
..A Winter Weather Advisory is now in effect from 4 PM Saturday Afternoon to 7 PM Sunday Evening for Northern Connecticut, North-Central Rhode Island and Norfolk and Suffolk Counties of Massachusetts for 3-6″ of snow and one-tenth to four-tenths of an inch of ice. It is noted that the next update could bring less snow but more ice for parts of this advisory area with a change to rain in southern parts of this advisory area before a change back to snow and ice and a flash freeze before ending..
..A Winter Weather Advisory is now in effect from 4 PM Saturday Afternoon to 7 PM Sunday Evening for South Coastal Massachusetts and Rhode Island for 1-3″ of snow and up to one-tenth inch of ice before a changeover to heavy rain before a change back to snow and ice and a flash freeze before ending. Wind Gusts of 40-45 MPH are possible in this area..
..A Coastal Flood Warning remains in effect from 8 AM-Noon for Eastern Essex, Suffolk, Eastern Norfolk and Eastern Plymouth Counties of Massachusetts for flooding of vulnerable shore roads and possibly isolated pockets of minor property damage at the time of high tide Sunday Morning..
..A Coastal Flood Advisory remains in effect from 8 AM-Noon for for Cape Cod and the Islands for flooding of vulnerable shore roads at the time of high tide..
..A Coastal Flood Advisory remains in effect from 5 AM-10 AM for South Coastal Massachusetts and Rhode Island for flooding of vulnerable shore roads at the time of high tide..
..Urban and poor drainage flooding could become a concern along Southeast Coastal Massachusetts, Rhode Island extending to the interior of Southern Rhode Island and Southeast Massachusetts and including Cape Cod and the Islands. The Cape and Islands could also see wind gusts to around 50 MPH during the storm..
..SKYWARN Activation with Ops at NWS Boston/Norton are likely at some point Saturday Evening into Sunday Morning lasting through Sunday Evening. Activation plan will be updated in the next coordination message..

The long quiet period of winter weather with only some strong wind, heavy rainfall events and a few very light snow and ice events is on track to come to an end. The headlines discuss the current potential and a second cut at snow and ice totals. Some key factors still remain for the upcoming storm and the model trends are shifting to a warmer and icier solution for much of interior Southern New England based on a partial model guidance update. Further updates could occur as we move into later this afternoon. The key factors remain as follows with some updates:

1.) The storm track will determine the area of all snow and where it will be a very heavy snow accumulation, where precipitation mixes with sleet and/or freezing rain with potential sleet and/or ice accumulations and where a changeover to rain occurs. Locations that changeover to rain or sleet and freezing rain will see a changeover to snow before ending with a potential for a flash freeze condition where all wet surfaces will become iced over. At this time the trend continues to be for more sleet and freezing rain particularly along and south of the Mass Pike and potentially from I-495 west but it is now possible it could extend as far north as the Worcester, Springfield, Northamton, Mass area. While this may lower snowfall amounts, the icing will have the potential to cause worse conditions including potential for pockets of tree and wire damage and power outages. Further snow and ice total adjustments will be made before the storm and possibly during the storm as required.
2.) Strong winds will be possible to likely in coastal areas but currently expected to be wind gusts up to 50 MPH. Inland areas could see wind gusts to 40 MPH. Some of this could change based on the intensity of the storm system and the track. That could affect both wind speed intensity and duration of strong winds. There will also be strong winds as the storm departs Sunday Night into Monday Morning.
3.) The snow could be heavy and wet along with the potential for sleet and freezing rain. The weight of the snow and ice coupled with the winds to some extent may cause the potential for isolated to scattered pockets of tree and wire damage and power outages. This aspect will be monitored closely and as mentioned previously, if snow amounts are lowered, ice amounts increase in most areas which could actually lead to greater impact and will be monitored closely.
4.) Minor to moderate coastal flooding is possible on the Sunday Morning high tide cycle in East Coastal Massachusetts where a Coastal Flood Warnings and Advisories are now in effect. While winds are not expected to be as strong as some past nor’easter/coastal storm systems, there is a very high astronomical tide cycle for this weekend which will increase the coastal flood potential.
5.) Spotter reports on snow, ice, amounts, wind measurements of criteria and any damage reports will be critical as well as precipitation type reports when the changeover takes hold. This will factor into forecast adjustments if needed during the storm event.
6.) How these key factors line up and turn into specific outcomes will be better defined after the afternoon model guidance.

SKYWARN Activation with Ops at NWS Boston/Norton are likely at some point Saturday Evening into Sunday Morning lasting through Sunday Evening. Activation plan will be updated as we get closer to the storm event. The next coordination message will be posted by 900 PM Saturday Evening. Below is the NWS Boston/Norton Winter Storm Warning/Watch statement, Coastal Flood Warning/Advisory Statement, Hazardous Weather Outlook, Enhanced Hazardous Weather Outlook, Snow and Ice Maps:

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

NWS Boston/Norton Coastal Flood Warning/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 Snow, Ice and Rain Maps:
https://www.weather.gov/box/winter

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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