New York and Boston were hit hard by last weekend’s monster winter storm, so the thought of another big snowstorm sends shivers down the backs of a region already pushed to the brink by back-to-back storms.
Fortunately for big cities like New York, Philadelphia, and Washington, this weekend’s nor’easter will not have a significant impact. That means road crews can continue work to clear away last weekend’s snow that remains piled up wherever they can stash it.
Any meteorologist will tell you that the East Coast’s biggest snowstorms come in the form of an old-fashioned nor’easter. Low pressure develops off the East Coast and charges north, spreading heavy snow to areas along the coast. This is how the heavily-populated Interstate 95 corridor gets its big snows.
So why won’t this weekend’s storm deliver blockbuster totals? Forecasters use something called the “benchmark” to help them determine whether or not the Northeast and Mid-Atlantic will get blasted by heavy snow. The benchmark is the so-called “40/70 benchmark,” located at 40 degrees north latitude and 70 degrees west longitude. For reference, that’s some 80 miles south of Massachusetts’ Nantucket Island.
When a low-pressure system hits the “40/70 benchmark”—that meteorological sweet spot off the coast—and meets deep sub-polar air, the result is often a regional blockbuster. This precise path is the DNA of a true East Coast legend; it’s the same track used by the historic Blizzard of ’96 to bury the I-95 corridor, from D.C. to Boston, under feet of snow.