“New England Will Be Closed” – Blizzard of ’13 Update

Blizzard update from Paul Douglas and AlertsBroadcaster:

…this storm will negatively impact more people in the northeast than even Superstorm Sandy did in late October and early November. Although coastal flooding won’t be nearly as severe, the impact of heavy snow, high winds and potential power outages will result in a very high-impact weather event for New England and metro New York City. 23 million Americans are under a Blizzard Warning right now.

Although computers have been converging (slowly) around a final solution, there is lingering uncertainty. This should be a plowable snowfall for New York City, enough to shovel and plow meaning at least 4-8″. Recent computer models are hinting at considerably more than that, especially for New York’s northern and eastern suburbs. By the time the 2 storms phase into one (monster) the heaviest precipitation shield may be just north/east of New York City. That, and 42 F. water temperatures in the Atlantic off the coast of New Jersey and Long Island may keep precipitation falling as a cold rain into the evening hours. The faster the changeover to all snow late Friday, the greater the ultimate snow amounts will be. I still believe a foot or more is likely in the city, with as much as 15-20″ from north Jersey into Westchester and Fairfield Counties. Eastern Long Island may also pick up some 15-20″ amounts.

1+1=3.

Much like Sandy we have an imminent convergence of two weather systems; a clipper-like system approaching from the Great Lakes will merge with a developing coastal storm over the Carolinas. The northern storm provides much of the energy, while the southern storm provides a jolt of southern moisture, spiked with moisture off the Atlantic. That’s why the weekend storm will be formidable: impacting such a huge area with 1-3 foot snows.

Snowfall Predictions. I realize, at first glance, this looks like a map of current temperatures. It’s not. This is the latest (Bufkit/Cobb Method) snowfall prediction from NOAA’s NAM weather model; as much as 25″ for the northern/eastern suburbs of New York City, 23″ at Portland and 31″ for Boston. I can’t remember seeing an area of 18″+ predicted snowfall this big in the last 20 years. This will be an historic storm. Paralyzing, and historic.

Climate deniers, of course, will have difficulty processing snow in a warming world.
A senior atmospheric scientist writes me:

I looked at this and the SSTs right along the coast in New England are 1 to 1.5C above the 1981-2010 normal, more generally SSTs are 0 to 0.5C above that normal. But of course that normal is 0.5 C above the 1951-80 normal.

So, yes the higher SSTs will add 10% to the snow, but the key thing is biggest snows occur when temps are just below freezing, which seems to be the case. So the atmosphere is loaded with max moisture possible and still producing snow.

And it’s a strong storm.