Tens of millions under winter storm watches ahead of weekend nor'easter

On Thursday morning meteorologists continued to pour over all available forecast model data to be able to provide more details regarding the expected timing and effects of the weekend winter storm for the East Coast.

Less than two days before the start of the storm, local National Weather Service offices put up Winter Storm Watches to begin outlining what to expect.

The suite of forecast models were still not in agreement on the track of the storm, leading to a still wide range of expected snowfall totals. The uncertainty around snowfall totals was especially high for cities like Philadelphia and New York.

The National Weather Service office in New York presented the possibility of 6 to 12 inches of snow across their forecast area between the period of Friday night and Saturday evening.

Given the aforementioned low confidence in expected snow totals, however, they took care to provide this clear and concise language surrounding the uncertainty within their Winter Storm Watch, "There continues to be greater than usual forecast uncertainty with the track of this storm, and the axis of heaviest snowfall may shift in subsequent forecast updates."

Storm Timing

The snow is expected to begin late Friday along the East Coast as the coastal storm intensifies off the coast. Through the night, the coastal low is expected to rapidly intensify over the Atlantic increasing the risk for strong winds and coastal flooding along the coast.

Saturday will be the highest impact day, with heavy snow and strong winds expected especially for locations from eastern Long Island up through coastal New England.

Per the current forecast, snow is most likely to end by early afternoon from Philadelphia to New York and around midnight for Boston. All snow will be off the Maine coast by early Sunday.

Areas most likely to experience a significant and high-impact snow event included eastern Long Island up through southern New England (including Cape Cod) to Maine. Those are the regions most likely to experience a foot of snow or more and the highest wind gusts leading to potential blizzard conditions.

The National Weather Service in Boston outlined the potential for total snow accumulations of 8 to 17 inches and winds that could gust up to 60 mph, especially on Cape Cod.

As forecast models continued to converge, meteorologists stressed that snow forecasts still had low confidence as of Thursday morning, and that adjustments would be possible. They emphasized monitoring the forecast for subsequent updates.

Forecasters urged the zone of highest uncertainty was along the I-95 corridor, especially from New York City and points south.

In addition to a nor'easter, the upcoming weekend will also feature very cold arctic temperatures that will spill all the way down to South Florida.

On Thursday morning, nine million people were under wind chill advisories across parts of the interior Northeast and New England. In these areas wind chills were as cold as 15 to 30 degrees below zero.

High temperatures were expected to moderate slightly on Thursday and Friday afternoon, but cold weather was expected to continue into the weekend.

The coldest temperatures are expected Sunday morning when lows across much of the state will dip into the 30s and wind chills could be in the 20s. Miami was forecast to dip to a low of around 40 degrees with wind chills in the upper 30s.

If Miami’s low Sunday drops to 39, that will be the coldest day since December 2010.