Morning Update, December 26, from NECN Meteorologist Matt Noyes
Summary: No major changes. Blizzard conditions expected for many areas. Widespread power outages owing to wind/heavy snow weight damage. Snowfall totals of 18"-26" are likely in many interior locations of Southern New England. Amounts will be less north, ranging from 4"-6" in far northern VT/NH/ME to as much as 24" south.
Confidence: High confidence on 15"+ event widespread. Moderate to high confidence of 18"+ event. High confidence on blizzard verification.
Variables: Significant deviations are not expected. A coastal front will result in a change to mix and rain in SE MA and Cape Cod. Biggest question is how far inland this penetrates around Boston/North Shore, but not expected to move very far inland there.
Timing: Light snow is underway in some communities, but this is well in advance of the main snow shield. Heavier snow continues developing CT/RI/Southern MA through 1 PM, spreading through Southern VT, Southern NH and Southern ME through dinner. Heaviest snow falls Sunday evening through Monday mid-morning, though at least some snow will linger until mid-afternoon in Eastern New England, later in Maine.
Intensity: Generally speaking, heaviest snowfall rates of 1"-3" per hour, locally up to 4" per hour in potential thundersnow, will occur between 6 PM Sunday (south) and 5 AM Monday.
Accumulation: Many communities should receive between 18"-26" of snow - with lower amounts for some coastal communities, and especially in far Southeast MA. An isolated maximum of 30"-31" is possible along Route 95 or 495 between Dedham MA and Southern NH. More exact placement of such a small focal point is impossible at this point. Nonetheless, if this localized maximum verifies, a few communities may see record 24 hour snowfall amounts, though that may not occur at an official observing station.
Other concerns: Widespread power outages are likely due to high wind, and weight of heavy snow, particularly in Southern and Eastern New England. Some power outages may last a few days in harder hit communities, not so much because of widespread infrastructure compromise as in the ice storm, but rather owing to the fact that line crews will have to dig through 2 feet of snow to find the power lines. High confidence on minor coastal flood event for flood-prone northeast facing shorelines. Moderate confidence of scattered pockets of moderate coastal flooding, primarily along the South Shore of MA.
Impacts: Roads will deteriorate quickly Sunday afternoon and
evening, south to north. Travel should not be attempted overnight.
Problems at Logan Airport will only compound through Monday morning.
Power outages will be a story starting late Sunday evening and lasting
through Monday. Clearing of exhaust vents for houses will be important,
as these snowfall totals will result in potential carbon monoxide
poisoning issues. The quantity of snow poses significant risk for those
shoveling and in poor physical condition or with a heart condition. As
for the coastal flooding, the 3 AM high tide is nearly identical in
height to the following 3 PM Monday tide, and both may bring minor to pockets of moderate flooding to prone northeast facing shorelines.