A couple of systems will bring wintry weather to the Mid-Atlantic region and while neither may be major snow producers, they both can be quite impactful. It appears each of these two systems may bring some snow and ice to the DC-to-Philly-to-NYC corridor in the period from Sunday night into late Tuesday. One disturbance will arrive on Sunday night with precipitation mainly in the form of snow north of the PA/MD border and a mix of snow and ice south of the Mason-Dixon Line. A second and stronger system with more moisture will bring snow, ice and rain to the Mid-Atlantic region from late Monday afternoon into late Tuesday. Given the expected combination of snow and ice and the cold ground-level conditions, roads may become an issue for commutes on both Monday and Tuesday in much of the region. Accumulations of up to a few inches of snow and ice are possible with each event north of the PA/MD border and from a coating to an inch or two south of the PA/MD border.
By Sunday afternoon, the first system will be spreading snow across the Midwest and Ohio Valley and precipitation will make its way into the I-95 corridor region of the Mid-Atlantic on Sunday evening. It should be cold enough for primarily snow in areas north of the PA/MD border though some ice can mix in at times. To the south of the Mason-Dixon Line, a mix of snow and ice is likely tomorrow night.
Round 2 may begin as early as late Monday afternoon as the second and stronger wave moves in from the west. Copious amounts of moisture will spread northeastward towards the Mid-Atlantic region from the Tennessee and Mississippi Valleys and it may very well be cold enough at first for snow to break out north of the PA/MD border, likely the precipitation will be a mix of ice and rain south of the PA/MD border. By late Monday night and early Tuesday, one area of low pressure (primary) will be heading towards the Great Lakes while a secondary surface low pressure system takes shape near the Mid-Atlantic coastline. Also, a strong high pressure system will be strengthening over southeastern Canada - a key player here - and funneling cold air into the Mid-Atlantic. Given this scenario, somewhat milder air could push northward along the eastern seaboard – at least in upper parts of the atmosphere – and any snow and/or ice is likely to change to a period of plain rain. However, temperatures may then drop some later in the second event as the high strengthens to the north and ice and/or snow could mix back into the picture; especially, north of the PA/MD border.
Bottom line…quite a wintry mess to start the new work week.
Meteorologist Paul Dorian