2:30 PM | *Storm threat continues for late Sunday and Monday with significant snow accumulations still on the table for N and W suburbs*
All of the latest indications continue to point to accumulating snow in the northern and western suburbs of the I-95 corridor cities of DC, Philly and NYC early next week with several inches of accumulation on the table. Even the big cities can end up with important snow accumulations from this storm, but there may be an extended period of mixed precipitation before a changeover to all snow in those areas.
A major storm will cross the country this weekend generating heavy snow from Denver to St. Louis and by later Sunday, it’ll run into an atmospheric roadblock over the Ohio Valley forcing it to grind to a screeching halt. At this time, energy will transfer from the initial “primary” low to a “secondary” low just off the Mid-Atlantic coastline. This coastal storm will then gradually intensify as it moves east-northeast from later Monday into Tuesday.
The approximate timetable for this storm in the Mid-Atlantic I-95 region is late Sunday into late Monday. Precipitation is likely to move into the DC metro region during the early evening hours on Sunday, and then reach the Philly area in the overnight hours and NYC by Monday morning. While the initial precipitation can be a brief mix of rain, sleet and snow in the northern and western suburbs of these cities, it should change to all snow in those locations and significant accumulations are possible. In the big cities and to places just to their east, accumulating snow is possible, but there will likely be an extended period of mixed precipitation during the storm. The northward extent of the significant precipitation shield with this storm may not go much past New York City given the blocking pattern in the upper atmosphere across eastern Canada. In fact, at this time it does not appear that places up the coastline such as Boston or Portland will get any significant precipitation from this storm.
Stay tuned to thesiweather.com this weekend for updates as this event is still a few days away. While it’s not saying much, this could be the biggest snowfall of the winter season in parts of the Mid-Atlantic and the Monday morning commute may be adversely affected.