

Rain and snow forecast for according to the GFS model for 1 p.m. on Wednesday. Rain is in green and snow is in purple. Most of the I-95 corridor is shown in snow, though this might be more snowy than reality. (weatherbell.com)

Tuesday update: East Coast storm shaping up to be a travel nightmare

A major winter storm will likely impact much of the Eastern Seaboard beginning Wednesday morning — the biggest travel day of the year.

While forecast uncertainty is still high two days in advance, we offer a forecast of what locations up the East Coast can expect from Tuesday night into Thanksgiving Day. Whether or not this storm turns into a travel nightmare will depend heavily on where the rain-snow line sets up on Wednesday afternoon — something that has been difficult to pin down thus far.

However, most of the East Coast, and in particular the I-95 corridor, can expect at least rain, possibly mixing with or changing to snow during the later half of Wednesday. Interior locations — at least 30 miles west of I-95 — are very likely to see accumulating snow, and travel will be challenging.

Airport delays are likely up and down the Eastern Seaboard due to this storm.

Raleigh, N.C.



Click to enlarge. Chance of at least 2 inches of snow accumulation through Thursday morning. Colors start at 10% chance and increase by 10 thereon (e.g. Raliegh is in a 10% chance of at least 2 inches of snow). (NOAA Weather Prediction Center)

Rain will begin in the Raleigh, N.C., region Tuesday night and last through Wednesday morning and early afternoon. The rain could clear out altogether by Wednesday evening, depending on the timing of the storm.

If the flakes fly in eastern North Carolina, they are likely to be short-lived and will not accumulate in any meaningful way. Temperatures are expected to remain mostly above the freezing mark — around 40 degrees — for the duration of the storm. Some flurries are possible Wednesday evening and night when the temperatures drop, assuming a slower storm. Chances are the bulk of the precipitation will have cleared out of North Carolina before it gets cold enough to see any meaningful or disruptive snow.

The Weather Prediction Center is giving the Raleigh area a 10 to 20 percent chance of snow accumulation over 2 inches, and that chance is mostly on the northwestern side of the city. This is a low chance of snow accumulation.

Snow becomes more likely northwest in the Piedmont at higher elevations. Though with temperatures hovering around and above the freezing mark, accumulation is expected to be minimal, with little disruption to travel.

Whom to follow: Nate Johnson (Raleigh), Matt Engelbrecht (Greenville), and Brad Panovich (Charlotte) are a few of the meteorologists you can look to for North Carolina updates.

Washington, D.C. – Baltimore



Click to enlarge. Chance of at least 2 inches of snow accumulation through Thursday morning. Colors start at 10% chance and increase by 10 thereon (e.g. Washington, D.C., is in a 50-60 percent chance of at least 2 inches of snow). (NOAA Weather Prediction Center)

Precipitation starts in the D.C.-Baltimore region early Wednesday morning. Snow will mix in through the late morning and early afternoon starting in the northwest and moving toward the southeast.

We expect a rain-snow mix east of I-95, with a low chance of snow accumulation. In D.C., we’re forecasting about an inch of snow by Wednesday night, which will be wet and heavy. Baltimore may see a slightly higher total than D.C., but not by more than an inch. In the near northwest suburbs, the chance of accumulation grows, with the best forecast at around 1 to 3 inches of snow accumulation. In the farthest western and northwestern suburbs, expect more along the lines of 3 to 6 inches of snow.

This is a low- to medium-confidence forecast and will undoubtedly need to be adjusted over the next 24 to 36 hours. The Weather Prediction Center, for example, is forecasting a 50 to 60 percent chance of more than 4 inches of snow in the District itself.

In any case, the majority of of the rain and snow will fall between the hours of 10 a.m. and 10 p.m. on Wednesday in the D.C.-Baltimore region. If you need to travel on Wednesday, getting an early start will be your best bet.

A winter storm watch has not yet been issued for D.C.-Baltimore, though we do expect that to come at some point on Monday.

You can follow all of our winter storm updates here on the blog, or on Twitter.

Philadelphia



Forecast snow totals. (NWS Mount Holly)

Precipitation will likely start early Wednesday morning and last through Thursday morning. The heaviest precipitation will fall Wednesday afternoon into Wednesday night.

For Philadelphia itself, most of the precipitation is expected to fall in the form of rain, though snow will mix in on Wednesday night. A sharp gradient between rain and snow is expected, of course, roughly along the I-95 corridor. East of this gradient, only 1 to 2 inches of snow may accumulate, but west of the gradient, as much as 8 inches could fall, with higher amounts accumulating in the Poconos.

North of Philadelphia, a winter storm watch is in effect from Wednesday morning through Thursday morning for the northwestern counties of New Jersey and the Poconos of southeastern Pennsylvania, for snow accumulations of 4 to 8 inches. As of Monday morning the winter storm watch does not include the cities of Philadelphia or New York City.

Whom to follow: Gary Szatkowski of the Mount Holly National Weather Service office.

New York City area

While there is a chance for rain on Wednesday night, precipitation will begin in earnest in New York City on Wednesday morning, most likely after 6 a.m., spreading from the south to north. The heaviest precipitation in the NYC area will fall on Wednesday afternoon into Wednesday evening.

For NYC and Long Island, it will be too warm for snow during the day on Wednesday. Rain is expected to change over to snow in the evening hours and overnight between Wednesday and Thursday, when the temperature drops to the freezing mark.

The Weather Prediction Center is giving NYC a 60-70 percent chance of seeing 2 inches of snow accumulate — but this will likely be a slushy, wet snow.



Click to enlarge. Chance of at least 2 inches of snow accumulation through Thursday morning. Colors start at 10% chance and increase by 10 thereon (e.g. New York City is in a 50-60 percent chance of at least 2 inches of snow). (NOAA Weather Prediction Center)

Further inland, rain will change over to snow in the afternoon, with accumulations of 6 to 10 inches of snow for the inland lower Hudson Valley and northwestern New Jersey. Four to 8 inches of snow is forecast for the Connecticut interior. A winter storm watch has been issued for these areas from Wednesday morning through Thursday morning. According to the Weather Service, there is a low chance of a winter storm watch or warning for the coastal areas in the NYC region, including coastal New Jersey and Connecticut.

Boston



Forecast snowfall totals. (NWS Boston)

Light precipitation will begin in the Boston area in the form of rain as early as Tuesday night, but the storm won’t get cranking in earnest until Wednesday afternoon. Snow could begin to mix in as early as Wednesday morning, though it’s not clear at this point whether that will transition to all snow on Wednesday afternoon and evening for Boston itself and the surrounding coastal areas. Further inland, rain will turn to snow in the morning or early afternoon hours of Wednesday, and stay that way through the duration of the storm. Precipitation is expected to end by the morning hours of Thanksgiving Day.

A winter storm watch is in effect for western Massachusetts and northern Connecticut from Wednesday morning through Thursday morning. Six to 14 inches of snow accumulation is expected in these areas. Whether or not areas to the east get meaningful snow accumulation depends on where the rain-snow line sets up, which at this point is difficult to nail down.

The Weather Prediction Center has placed Boston in a 50 to 60 percent chance of at least 2 inches of snow. Further inland, the WPC is giving central Massachusetts, including Springfield and Northampton, a 70 to 80 percent chance of seeing 8 inches of snow or more.

Whom to follow: Eric Fisher covers Boston area weather for CBS.