Good evening everyone,
Here is our latest thinking on the upcoming significant winter storm just beginning to affect Southern New England, continuing to do so through early Tuesday.
Watches/Warnings/Advisories:
1) NEW: Winter Storm Warning expanded to include Western Essex, Southeast Middlesex and Eastern Hampshire counties in MA for this evening.
What we expect:
Changes: Increased snow and ice amounts. Stressing two rounds of heavy snow: tonight into overnight interior MA/northernmost CT, and Monday night into Tuesday eastern/northeast MA. Other than western and central MA where lighter snows are expected to continue, mostly rain is expected elsewhere through late afternoon Monday.
Tonight into early Monday
- Snow becomes heavy at times (1"/hour) shortly after onset and continues into the evening hours.
- Precipitation changes to sleet and freezing rain in northern CT, RI, to a sleet/snow mix in northern MA, and to plain rain in southern RI and southeast MA for the overnight hours.
- By daybreak Monday, snow/sleet accumulations of 6-8" possible in western and northern MA with approximately 4-6" in Springfield and interior Essex County, with 2-5" elsewhere (including MetroWest Boston), except less than an inch on Cape Cod/Islands and near the immediate coast in southeast MA and southern RI.
- The snow will be very moisture-laden. This could make for compact snow but it will be heavy to shovel.
- Wind gusts will increase to 25-40 mph along the south coast late Sunday night.
Monday Night into early Tuesday
- Continued/ongoing snow in interior western/central MA will spread into eastern MA, northern CT and RI Monday night. Lighter, more manageable snows expected in central and western MA and northern CT/RI. However, snow is expected to increase in intensity Monday night into Tuesday across eastern and northeast MA, with 1"/hr snowfall rates possible in these areas.
- Impacts to the Tuesday morning commute are possible.
Winds and Minor Coastal Flood Potential:
- Winds will gust to 35-45 mph along coastal areas, with the highest gusts over Cape Ann, outer Cape Cod, and the coastal waters off eastern MA.
- Storm surges of up to 2 feet are expected, but due to low astronomical tides, only splashover is expected for east coastal MA, including Cape Cod Bay and Nantucket (with northeast winds). Will keep a close eye on this as some pockets on minor coastal flooding cannot be ruled out.
Storm Total Accumulations:
- We are still expecting a widespread 8 to 12 inches over much of interior MA with as much as a foot possible in the higher Worcester hills and 12 to 17 inches in the east slopes of the Berkshires and into areas near/north of Route 2 into northeast MA. These snow amounts are for both periods of heavy snow combined. Amounts drop off rapidly as one heads southeast, with 3 to 5 inches from southern Hartford County eastward to Providence and Plymouth and less than an inch on Cape Cod and the Islands.
Confidence :
- Confidence is highest in the warning areas of western and northern MA, where >6" of snow in a 12 hour period or 8" in a 24 hour period is likely. Confidence decreases moving into I-495 and towards the coast, where east winds contributing to temperatures near or just above freezing become offset by heavy precipitation rates.
- Confidence is moderately high for the second round of heavy snow Monday night/Tuesday period in eastern MA. How far west these snowbands extend is uncertain, which could affect snowfall totals in the Monday night to Tuesday period.
-- Andrew Loconto/Frank Nocera