Here is a breakdown by metro region in the Mid-Atlantic’s I-95 corridor as to what to expect during this upcoming long duration major winter storm:
DC metro region:
Snow develops early Sunday morning in phase 1 of this upcoming event and continues for much of the day with several inches of accumulation likely during this “overrunning” stage. In fact, phase 1 could turn out to be the time period with the “best” accumulating snows in the DC metro region although I do expect some additional accumulations from “wrap around” snow associated with the coastal storm (i.e., during phase 2). The snow will tend to lighten up at day’s end or by early Sunday night and the precipitation will also become mixed with ice or rain and it should continue in a spotty fashion into Monday morning. Any mixed precipitation will then likely change back to all snow later in the day on Monday as colder air wraps around from the north/northeast and it should continue as snow into early Tuesday with some additional accumulations likely. Total snowfall estimates for the DC metro region: 6-12 inches.
Philly and NYC metro regions
There can be a snow shower or two in the morning on Sunday, but the steadier snow should develop during the mid-to-late afternoon hours for the Philly metro region and by early evening in the NYC metro region. The snow will continue tomorrow night, but it could become mixed with sleet and/or rain late at night and into the morning hours on Monday. As colder air wraps in from the north/northeast, any mixed precipitation on Monday morning will change back to all snow by later in the day and should continue as snow on Monday night and into the day on Tuesday. In fact, the heaviest snow is likely to take place from later Monday into early Tuesday with significant accumulations. In addition, the winds will increase markedly as well later Monday resulting in some blowing and drifting of the snow and those strong winds will continue through Tuesday. Total snowfall estimates in the Philly and NYC metro region: 12-18 inches and there can be isolated higher amounts. These potential isolated higher amounts would be in those spots that experience “mesoscale” or small-scale banding containing brief bursts of intense snowfall and possible thunder.
Comparisons with the blizzard of January 1996
This unfolding scenario has many similarities in the upper part of the atmosphere to the blizzard of January 1996 which became the biggest snowstorm ever for many locations in the Mid-Atlantic region including Philadelphia, PA where 31 inches fell between the 6th and the 8th. The January 1996 blizzard featured a “closed-off” upper level low over the Ohio Valley, strong energy rotating through the base of an upper-level trough, and the formation of an intense coastal storm with entrenched Arctic air in place and so should the upcoming storm. In addition, the January 1996 blizzard featured strong ridging of high pressure across the western US – a key component to east coast snowstorms – and this upcoming storm should as well.
Stay tuned for further updates as this is a complex storm system, but get prepared for a major winter storm of long duration in the Mid-Atlantic region.
Meteorologist Paul Dorian