The National Weather Service has initiated issuing Winter Storm Watches for portions of the northeast with the odds of a storm developing along the coast increasing; it’s possible that some may even see blizzard conditions before the storm exits the coast.
Right now, Winter Storm Watches have been issued for all of Delaware and New Jersey, southern Connecticut, Rhode Island, and Massachusetts, southeastern New York including the entire New York City metropolitan area and all of Long Island, much of southeastern Pennsylvania including the entire Philadelphia metropolitan area, and much of eastern Maryland including the entire metropolitan Baltimore area. The Winter Storm Watch is up for Sunday into Monday for the threat of heavy snow and snow accumulations exceeding 6″.
Latest data suggests a lot more than 6″ could fall, especially over central and southern New Jersey, eastern Long Island, Delaware, and southeastern Massachussetts, with some forecast model guidance suggesting snow in excess of a foot for many places.
The current expectation is for light precipitation to begin overspreading the Mid Atlantic from southwest to northeast some time overnight Saturday night. As the low begins to approach from the southwest Sunday afternoon, precipitation rates should begin to increase. Temperatures during the daytime hours on Sunday are expected to be fairly mild, so precipitation will likely be rain or a rain and snow mix for most of the day, especially for areas south and east of Trenton, New Jersey. Sunday night, colder air will begin to infiltrate the area in concert with the heaviest precipitation rates. Therefore, precipitation is likely to change to all snow, and be heavy at times. Snow will likely come to an end from west to east by Monday afternoon.
Snow could be very heavy at times, with rates exceed 1″/hour, especially along the coast of New Jersey and Cape Cod. There’s also the threat of thunder snow around the region which could lead to even heavier snowfall rates and the added hazard of lightning.
The National Weather Service currently expects total snow accumulations to be 4-6″ northwest of the I-95 corridor and across much of the Delmarva, and 6-10″ southeast of the I-95 corridor. They caution, though, “It should be noted that these amounts will likely need refined as the low track and positioning of other features such as the inverted surface trough come into better focus.” The inverted trough is a feature of the storm expected to form and bring especially heavy snow to portions where it does.
In addition to the heavy snowfall, as the low deepens Sunday
night into Monday, winds will begin to ramp up, with gusts 30-40
mph possible even well inland with higher gusts expected along the immediate coast.
“The snow will be on the wet and heavy side, which should temper blowing and drifting potential some,” says the National Weather Service. ” However, some blowing and drifting is certainly a possibility.”
Strong winds and heavy snow could create blizzard-like conditions at times. There is a clear difference between a winter storm, like the one that hit the east coast not long ago, with a blizzard. A blizzard is a severe winter storm defined by sustained winds or frequent gusts of 35 mph or greater, accompanied by heavy falling snow or blowing snow that reduces visibility to less than 1/4 mile. These intense conditions must persist for at least three consecutive hours to be officially classified as a blizzard.
The strong onshore flow is expected to lead to minor to moderate coastal flooding along the Atlantic and western Delaware Bay\ coasts with at least the Monday morning high tide cycle, and perhaps beyond. Coastal flooding and beach erosion are also possible for Long Island and the southeast coast of New England.
Heavy snow and strong winds can also take out trees, wires, or trees onto wires, resulting in power outages too. Gusty winds will linger into Tuesday before the next system arrives Tuesday night.
