The National Weather Service has issued Winter Storm Warnings and Winter Weather Advisories for tomorrow where Winter Storm Watches were up previously. The forecast has changed a bit and it now appears the winter storm will travel a bit more north than initially expected. This means heavier snow will fall farther north while southern areas will see more sleet. There’s also a threat of heavy snowfall rates and isolated thunder snowstorms.
Canadian high pressure will be situated off to the north to start the day tomorrow, locking in some low-level cold air over much of the northeast. Low pressure will move out of the Great Lakes region and travel southeast over Pennsylvania and New Jersey, crossing the Appalachians, and eventually moving offshore of the Mid-Atlantic by Saturday morning. As the surface low moves towards the coast, it will bring widespread precipitation to portions of the northeast and northern Mid Atlantic.
As with most storms, a battle will set up with relatively milder air and colder air. Much of this battle will occur high in the atmosphere where the form of precipitation is created and falls as snow, sleet, freezing rain, or rain. It appears the atmospheric profile will support all snow north of the Pennsylvania Turnpike and I-195 in New Jersey. South of here, enough mild air could push into mid levels of the atmosphere to produce sleet at times.
North of the all-snow, snow-sleet line, snow can be heavy at times. Snowfall rates may approach 1-2″/hour at times; there’s also a risk of isolated thunder snowstorms in this area, which would also help facilitate those heavier snowfall rates.
Generally, 6-8″ will fall in the heavy snow area from central and northern New Jersey into the New York City metro area and western Long Island and back into Pennsylvania and Upstate New York by the state line they share. With snow falling more north, 3-6″ is now expected as far north as central Connecticut and far southwestern Massachusetts. Light snow is now expected over northern New York, central and southern Vermont, and much of western Massachusetts.
On the southern side of the snow, around 3″ is expected for places like Philadelphia with less to points south. Snow isn’t expected south of northern Delaware or into West Virginia or Virginia. While no snow is expected there, some sleet is possible.
The snow will begin from west to east and end west to east, with snow wrapping up early Saturday. The balance of Saturday will be cold, fair, and dry in the wake of the storm as it heads out to sea.
Due to the storm, the National Weather Service has issued Winter Storm Warnings for Warren, Sussex, Passaic, Hudson, Bergen, Essex, and Morris counties in New Jersey, and Orange, Putnam, Rockland, Westchester, New York (Manhattan), Bronx, Richmond (Staten Island), Kings (Brooklyn), Litchfield, Greene, Ulster, Suffolk, Nassau and Dutchess in New York, and Fairfield and New Haven in Connecticut. Winter Weather Advisories are up for the rest of New Jersey except Cape May and southern Atlantic county as well as the rest of eastern Pennsylvania including Philadelphia; northern Maryland and Delaware are also included in the Winter Weather Advisory area.
