Summary:
Heavy snow is spreading into the D.C. area now, and will arrive in Baltimore shortly.  As snow accumulates and winds increase, blizzard conditions will develop in that region by late afternoon or early this evening, and will increase in severity into the nighttime hours.

Present indications suggest that snow will begin in the NYC area around 7-8pm, and rapidly increase overnight tonight.  Snow will then continue to spread Northeast into southern New England into Saturday and Saturday night.

Snow Impacts:

Impacts from snow will be very high to extreme within the lavender shaded area on the above image, which includes the Baltimore/Washington area, Philadelphia and northern Virginia, including areas near Richmond.

We continue to forecast 1-2 feet of snow on average within much of the lavender shaded area on the above map.  Some totals of 2-3 feet are possible in parts of this region, and drifting snow will be even higher than that in many areas.  Travel will likely become impossible within this area from late this afternoon into tonight and much of Saturday.  Blowing and drifting snow may continue into Sunday, which could extend the crippling travel conditions into late weekend.

**With this Update we have increased the forecast snow total range for the NYC area:

The area of maximum snowfall will be surrounded by an area of heavy snow generally in the 6-14 inch range including most of the greater NYC area, on East/Northeast into southern New England.  Localized total snowfall amounts of 14-18 inches are possible within parts of this same area (primarily from southern parts of NYC into Long Island), and it may become difficult to accurately measure amounts due to blowing and drifting in many areas.  Travel will become difficult at best in this region, mainly from tonight and on into the day on Saturday.   Blowing and drifting will continue into much of Sunday – well after the accumulating snow has ended.

Storm Total Snowfall:

 

 

 

 

 

We continue to forecast maximum snowfall of up to 2-3 feet within the area from northcentral Virginia into or near the Baltimore/Washington area.  The Baltimore/Washington area will likely be closer to the lower end of that range, with the higher end of that range more likely in northcentral Virginia.

The image below is a zoom-in of the above image, focused on the Baltimore/Washington area:

 

 

 

 

 

With this update we are slightly increasing the total snowfall forecast for greater NYC.  We continue to forecast a very sharp gradient on the northern edge of the heaviest snow band, and it continues to appear that the sharp gradient will cross West-East directly through the greater NYC area.  The heaviest snow in NYC will likely occur on the Southern tip of the city into western Long Island (with 10-14 inches likely).  Amounts will decrease drastically as you proceed to the Northern parts of the city, where closer to 6 inches of snow will likely occur.  Blowing and drifting will create greater snow depth at times in many parts of the area.

 

 

 

 

 

We continue to forecast that the heaviest snowfall for NYC will occur from tonight/pre-dawn Saturday on into the early to mid-afternoon hours on Saturday.  Strong and gusty winds will create considerable blowing and drifting throughout the day Saturday and into at least early Sunday – even after the accumulating snowfall ends.

Wind Impacts:

In addition to heavy snowfall, strong, gusty East to Northeast winds will cause widespread blowing and drifting snow across much of the same regions.  The potential also exists for damage to trees and power lines, which may result in power outages in the hardest hit areas.

 

 

 

 

 

The potential for more widespread impacts from the wind will likely occur within the lavender shaded areas on the above image, where wind gusts of 45-55 mph will be common at times during the peak of the storm.  This includes Eastern suburbs of the Washington DC and Philadelphia areas, as well as much of New Jersey and the Atlantic facing portions of central and eastern Long Island.  Within the red shaded area on the same image, peak wind gusts of 35-45 mph are possible at times.

Coastal Flooding and Beach Erosion:

The final significant impact from this storm is likely to come in the form of coastal flooding and beach erosion, which will be highest within the lavender shaded areas on this image:

We will continue monitoring the situation and issue updates as conditions warrant and as details become more clear.