March Madness continues in the Mid-Atlantic on Monday with a springtime snowstorm and perhaps the biggest snow event in a couple of years around here. A major coastal storm will affect the Mid-Atlantic region from tonight into early tomorrow night and significant snow accumulations are likely. Heavy snow is falling today across parts of the Midwest as one low pressure system heads towards the Ohio Valley. Meanwhile, heavy rain and thunderstorms have broken out across the Southeast US as a secondary low pressure system begins to take shape near the coastline. By tomorrow, the Ohio Valley primary low will begin to weaken as the secondary takes over near the Mid-Atlantic coast. This storm will then intensify rapidly on Monday as it slowly pulls to the northeast.
Precipitation should move into the DC region early this evening, then late this evening across Philly, and finally by very late tonight in the NYC metro region. The precipitation could start as rain or a mix of rain, sleet and snow at the onset, but should change to all snow fairly quickly; especially, in the northern and western suburbs of these three metro regions. The first wave of precipitation from this storm will come from the Ohio Valley primary low and then the coastal low takes over on Monday. In fact, the snow is likely to come down quite hard during the period from mid-morning to mid-afternoon on Monday after the coastal low takes over and the upper level dynamics reach their peak, and there is likely to be some disruptive effects on travel conditions. The snow can mix with sleet and rain at times on Monday; especially, during the afternoon hours in the big cities. The snow will be of the wet and heavy variety and the combination of the heavy, wet snow and intensifying northeasterly winds could lead to some power outages anywhere from Long Island to the Delmarva Peninsula. The storm does not look like it will ride up the New England coastline so Boston and Portland will likely be spared from any significant precipitation.
Preliminary snowfall accumulation estimates for the entire storm are as follows: 1-3 inches in the immediate DC, Philly and NYC metro regions and points south and east all the way to the coastline; 3-6 inches in the northern and western suburbs (outside the beltway in the DC metro region; Chester, Bucks, Montgomery Counties in the Philly area; northwestern NJ, Lower Hudson Valley near NYC).