NOAA: Morning storm update

Now forecasting 4-6 inches for most of Cape, high winds, coastal flooding
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Here is the morning update from the National Weather Service:

[Through Monday]

A powerful winter storm is expected to impact Southern New England through the course of today into Monday. Being thorough to keep you informed, here's our Sunday morning comprehensive briefing.

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Threats ...

SNOW ... beginning around 9 am to 12 pm, becoming moderate to heavy at times over a majority of S New England this afternoon into evening, a brief lull overnight before snowfall picks back up again early Monday morning, especially across E/NE/ Northeastern MA, continuing on into midday Monday. Reduced visibility down to a quarter mile or less. Snowfall rates of 1 to 2 inches per hour. Hazardous travel conditions. Power outages possible with the weight of snow on limbs and powerlines (this in addition to winds noted below). Highest amounts of around 12 to 18 inches forecast north of the MA-pike, especially over Northern and Northeast MA, with 6 to 12 inch amounts from the southern areas of the Boston-metro across Northern RI and Northern CT when all is said and done Monday evening. Lower amounts further south given mixing with sleet, freezing rain, and/or plain rain.

WINTRY MIX ... of snow, sleet and/or freezing rain, possibly also mixing with plain rain, across CT, RI and SE MA with coastal communities remaining as rain. Timing of the wintry mix is through this evening before all precipitation becomes snow. Some uncertainty which is noted below.

DAMAGING WINDS ... especially across E/SE-Coastal MA with northwesterly gusts up to 65 mph possible. Isolated to scattered power outages subsequent of strong winds in addition to the weight of snow on limbs and power lines. Strongest winds are forecast to begin early Monday morning and continue through evening. Greatest risk for damaging winds will be Cape Ann, Cape Cod and Nantucket. Important to note, a Blizzard Watch accounts for the high winds. In addition, across South-Coastal MA and Martha's Vineyard, a High Wind Watch has been posted.

COASTAL FLOODING ... focused within north- and west-facing beaches of Cape Ann and Cape Cod. A 1 to 3 foot surge is forecast. Minor to moderate coastal flooding with pockets of major expected, especially for communities along the northern coast of Cape Cod. Splashover. Inundation of vulnerable roadways. Beach erosion. Washouts. Possible structural damage. An advisory for this afternoon's high tide. A coastal flood watch for the late morning to early afternoon high tide on Monday when northwest winds will be at their strongest.

Uncertainty ...

What remains a bit uncertain is the strength and proximity of the low pressure center with respect to the eastern coastline of MA. The storm center is expected to rapidly strengthen in the Gulf of Maine. However a slight nudge closer to the coast, or away, ultimately changes a series of impacts across Southern New England with respect to the threats noted above.

One reason BLIZZARD WATCHES continue. There is some uncertainty as to whether east coastline communities of MA including Nantucket will experience blizzard conditions. However, highest confidence of blizzard conditions is across Essex County MA.

Another reason why a HIGH WIND WATCH was posted for South-Coastal MA and Martha's Vineyard. Given the uncertainty of the storm center, forecast winds across the aforementioned region may differ.

Some uncertainty on precipitation type for today into this evening. We feel confident as to the areas where dividing lines between rain, a wintry mix, and snow are forecast to develop. However specifically down to the detail remains a challenge. There is the possibility we may see an extended period of freezing drizzle / rain within the area of the forecast wintry mix. As we gain more confidence we'll continue to provide additional details.

When Will We Know More ...

As the latest forecast guidance becomes available, we'll re-evaluate our thinking and let you know as to any changes with the forecast, especially with respect to threats and impacts. welcomes thoughtful comments and the varied opinions of our readers. We are in no way obligated to post or allow comments that our moderators deem inappropriate. We reserve the right to delete comments we perceive as profane, vulgar, threatening, offensive, racially-biased, homophobic, slanderous, hateful or just plain rude. Commenters may not attack or insult other commenters, readers or writers. Commenters who persist in posting inappropriate comments will be banned from commenting on