![]() Date: 2024-08-16 Page is: DBtxt003.php txt00020204 | |||||||||
Weather | |||||||||
Burgess COMMENTARY Peter Burgess | |||||||||
Original article:
https://www.washingtonpost.com/weather/2021/01/31/snowstorm-new-york-philadelphia/
Capital Weather Gang Blockbuster snowstorm to strike New York, Philadelphia For some, the snow may be measured in feet rather than inches, especially away from the immediate coast The National Weather Service's snowfall forecast. (WeatherBell) The National Weather Service's snowfall forecast. (WeatherBell) A high-impact winter storm is set to take aim at the Northeast beginning late Sunday and continuing at times into Tuesday, plastering the corridor from Philadelphia to Boston with heavy snow, including New York City. Widespread snow totals nearing or exceeding a foot are possible from Philadelphia to Boston, with 18 inches or more not out of the question in New York, depending on any influx of relatively mild air from the Atlantic Ocean. The same storm system has already brought eight inches of snow in Chicago and will drop a healthy dose of snow all the way to the Canadian border on Sunday. The low-pressure area that will bring the heavy snow, strong winds and potential for coastal flooding to the Northeast will spend Sunday getting organized in the Mid-Atlantic region, where snow was falling in the nation’s capital. Washington was poised to receive more snow in one day than the city has seen in two winters. Live updates: Snow blanketing D.C. area; several inches expected Sunday The winter storm has a history of spawning wild weather across the Lower 48, first driving an atmospheric river ashore in California last week with extreme snow totals topping 100 inches in the Sierra Nevada. From there, it brought severe thunderstorms to the Desert Southwest and tornado activity to Oklahoma, while a dust storm in its wake caused visibility to plummet Saturday in parts of Texas. Water vapor imagery shows a low-pressure system over the Great Lakes transferring its energy offshore to a developing low east of the Delmarva Peninsula early Sunday. (College of DuPage) Water vapor imagery shows a low-pressure system over the Great Lakes transferring its energy offshore to a developing low east of the Delmarva Peninsula early Sunday. (College of DuPage) Now the main low-pressure area is transferring its energy offshore into a coastal system, also known as a nor’easter, that will intensify and move northward up the coast. Winter storm warnings for heavy snow were in effect from the mountains of North Carolina through southwestern Connecticut, while watches extend all the way to extreme-northern Maine. Storm ramps up in Northeast as steady snow moves out of D.C. area A high-resolution model simulation of snow targeting the Northeast. (Pivotal Weather) A high-resolution model simulation of snow targeting the Northeast. (Pivotal Weather) Snow is likely to move into Philadelphia by 4 or 5 p.m. Sunday, with snowfall rates increasing rapidly as the offshore low-pressure system begins to strengthen. Moderate to heavy snow is likely there by late evening, with numerous computer models showing a band of extremely heavy snow forming between Philadelphia and Rhode Island from Sunday night into Monday. There is a chance that milder marine air drawn inland by the counterclockwise winds around the low-pressure center may flip Philadelphia over to mixed precipitation, including sleet or freezing rain, during the wee hours of Monday morning, before precipitation changes to rain and temporarily ends. Snow will fall heaviest immediately before that changeover, with snowfall rates of at least an inch per hour. Snow in D.C.’s Rock Creek Park People came to enjoy the snow on Jan. 31 in one of the nation's oldest national parks. (The Washington Post) In New York, snow will arrive by late evening Sunday, with heavy snow and possible thundersnow during the morning hours on Monday. Significant uncertainty exists regarding a potential changeover to a wintry mix or rain around noontime, however. If that transition does occur, snowfall amounts would stack up to a bit more than a foot. But if the changeover doesn’t occur, more significant accumulations would be likely in the Big Apple — perhaps on the order of 18 inches or closer to two feet. The Weather Service's call for snow through early Tuesday morning. Note that snow will still be ongoing in Maine at this point. (Pivotal Weather) The Weather Service's call for snow through early Tuesday morning. Note that snow will still be ongoing in Maine at this point. (Pivotal Weather) The National Weather Service included New York in the level 5 out of 5 “extreme impact” zone on their outlook map, citing the potential for “extreme disruptions to daily life.” Most of the surrounding Tri-State area can anticipate “major impacts” from the storm system, which looks to produce potentially blockbuster snowfall totals. In Boston, it’s also shaping up to be a high impact storm away from the immediate coast, with well over a foot of snow expected just inland. One particular high-resolution computer model, known as the North American Model (NAM), suggests that cold air would remain entrenched in New York for the duration of the event. During the day on Sunday, other computer models aligned with this model’s projections, showing a potentially historic snowstorm there. Such heavy snowfall could shut down city streets and cancel flights at the region’s major airports. “Despite the fact that we are forecasting up to 18 inches of snow, these numbers are conservative if you trust the NAM,” wrote the National Weather Service in New York. “The NAM suggests that 2 ft is reasonable for this event where the heaviest band sets up and where it remains mostly snow.” If New York were to pick up 19.8 inches or more in 48 hours, it would qualify as one of the top 10 heaviest snowfalls on record in the city. The top spot of 27.5 inches is held by the Jan. 22-23, 2016, storm. Regardless, snowfall amounts will vary significantly depending on where the narrow corridors of heaviest snowfall, known as snow bands, set up and stall. In the heaviest bands, snowfall rates of one to two inches per hour or more are likely. Eastern Pennsylvania is also likely to see very heavy snowfall, including in such places as Harrisburg and Allentown, in the east and onto the western Philadelphia suburbs. There’s the possibility that places in northern New Jersey could see more than two feet of snow, as moisture from the Atlantic Ocean is drawn westward, directly into much colder air. Snow will ease overnight Monday into Tuesday, but light snow is still likely most of Tuesday morning into the afternoon. The jackpot of snow may occur in New York City proper, while also encompassing the southern Hudson Valley and most of central and eastern Pennsylvania. Providence to Boston: A forecast conundrum In Hartford, Conn., the snow should stack up to six to 12 inches, with the potential for higher totals. Farther northeast, in the Providence-to-Boston corridor, meteorologists were grappling with predicting the finicky rain-snow line. Heavier snow will arrive there by Monday mid-morning, with the height of the storm occurring overnight before winding down on Tuesday. During the storm, the rain-snow line may wiggle back-and-forth near Interstate 95, with a touch of mixing possible in Boston and Providence, R.I., despite predominantly snow falling. For the South Shore, Upper Cape and Plymouth and Bristol counties in Massachusetts, a quick burst of snow will give way to mainly rain. Storm totals of 12 to 18 inches are expected just west of Boston, with the biggest wild card being the amounts in Boston itself and along the immediate coastline. With onshore winds of up to 60 miles per hour, high waves and coastal flooding will affect the New England shoreline as well, leading to the potential inundation of vulnerable areas. The storm is even expected to spread snow into northern New England, benefiting ski areas in Vermont, New Hampshire and Maine. Conditions will improve later Wednesday before milder weather late in the week. 210 Comments Headshot of Matthew Cappucci Matthew Cappucci Matthew Cappucci is a meteorologist for Capital Weather Gang. He earned a B.A. in atmospheric sciences from Harvard University in 2019, and has contributed to The Washington Post since he was 18. He is an avid storm chaser and adventurer, and covers all types of weather, climate science, and astronomy.Follow Headshot of Andrew Freedman Andrew Freedman Andrew Freedman edits and reports on extreme weather and climate science for the Capital Weather Gang. He has covered science, with a specialization in climate research and policy, for Axios, Mashable, Climate Central, E&E Daily and other publications. Follow |