New York City sets record for lack of snowfall
A storm system is expected to develop off the southeast coast on Saturday night. On Sunday, it is expected to move northeast as it intensifies and throws precipitation westward, before moving off the Mid-Atlantic coast on Sunday evening.
How far offshore and how far north the storm travels are key.
The best chances for heavy precipitation extend from South Georgia to the Eastern Carolinas and Southeastern Virginia. Some heavy precipitation could spread to the rest of Virginia, as well as the District, Maryland and Delaware, but confidence in how far north and west precipitation will reach is low.
Rain is probably the primary type of precipitation. But accumulating snow may fall on the western and northwest fringes of precipitation.
Stormtrack will determine how much precipitation and where
Washington and locations to the north may experience heavy precipitation or be fringed by some lighter rain. Forecast models over the past 24 hours tend to shift the storm’s track slightly further north and west, increasing the likelihood of precipitation around Washington and Baltimore.
“[M]Winds wrapping around the well-developed low now have the potential to produce heavier weekend rains and stronger winds from the southeast to at least the eastern Mid-Atlantic and coastal New England,” the National Weather Service wrote Wednesday morning. early.
While model forecasts have shifted further north and west with the storm track, that trend may not continue and may even reverse, meaning the impact will be smaller. We see three plausible scenarios, the first two being perhaps the most likely:
- The storm follows close to the coast. A trail along the South Carolina coast to near Cape Hatteras and then northeast could bring heavier precipitation on Sunday through the Interstate 95 corridor into the Washington-Baltimore area. The I-95 corridor will likely see mostly rain, but colder areas in the west and southwest may transition to sleet, especially in the Appalachians.
- The storm fringes the major cities. A track further offshore could limit precipitation in major cities, favoring heavier amounts in areas east of I-95 and especially over the Carolinas and Southeastern Virginia. Snow accumulation would mostly be confined to the mountains of western North Carolina and southwestern Virginia.
- The storm does not gather and is at sea. Several high-altitude weather disturbances must intermingle to produce the storm. If they don’t, no significant storm would form and mostly dry weather would prevail north of the Carolinas.
While some snow cannot be completely ruled out east of the Appalachian Mountains, cold air is so limited that meaningful accumulation away from the mountains is unlikely.
Northeast confronts the weather with a whiplash, with a record warming after a record cold
“Gathering snow around Washington is still a gamble as low temperatures are likely to remain above freezing,” wrote Capital Weather Gang winter weather expert Wes Junker. “There is no cold air source.”
In an ideal situation for snowfall in the Mid-Atlantic coast, strong high pressure to the north would carry cold air to the area as a storm develops offshore. In this case, there is minimal high pressure and generally above normal temperatures throughout the Northeast and into Canada.
For snow in the DC area of this event, the storm should follow a track so that a small pool of high-altitude cold air and heavy precipitation passes directly overhead. In that scenario, through a process known as dynamic cooling, rain can mix with or turn into sleet for a period of time.
“We would need heavy precipitation to fall with a perfect trajectory,” Junker wrote. “The best chances for accumulations are where the elevation keeps the temperature a little bit colder and around I-81.”
The potential storm would come after several days of high temperatures around and above 60 in Washington and Philadelphia, with peaks well into the 50s north of these areas. It is also followed by warm air in the days after it passes.
January’s warmth was unprecedented across much of the Northeast
For now, the bottom line is that there’s no major reason to worry that a major snowstorm will seriously disrupt plans for Super Bowl Sunday. Rain can certainly bother a wide swath. Details about the storm and its potential should become clearer in the coming days.