The storm was a textbook bomb cyclone, meaning its minimum central air pressure intensified by at least 24 millibars during the span of 24 hours. This particular weather system drastically overachieved in terms of its rate of pressure drop. In general, the lower the air pressure, the stronger the storm. A preliminary look reveals this system managed a 34-millibar drop in 22 hours.
Boston, Providence, Nantucket and Concord in Massachusetts, and Portland, Maine, all smashed records for their lowest October air pressure readings on record, and some of these were set by a large margin.
For example, in Boston the barometer bottomed out at 975.3 millibars. Boston’s previous October record was 980 millibars; the city has records dating back to 1893. Between 1 and 3 a.m. Thursday, the pressure at Boston’s Logan Airport fell 11.9 millibars in two hours — a rate of 6 millibars per hour.
Such a rapid air pressure drop powered furious winds rivaling those coiled within New England’s nastiest blizzards and hurricanes, knocking down trees and power lines. The damage was significant enough to force schools to close in a number of Massachusetts districts.
Winds gusted to 90 mph in Provincetown, at the tip of Cape Cod. Nearby Wellfleet had a wind gust to 89 mph. Elsewhere on the Cape Wednesday night, Mashpee and Yarmouth peaked at 78 mph and 79 mph respectively.
The system was somewhat unusual, in that it did not take the typical path of a nor’easter. The low-pressure center tracked inland over southeastern Massachusetts, moving up the Blackstone Valley west of Boston, rather than over the Cape Cod Canal or off the coast of Massachusetts.
This track meant its strongest winds were focused beneath the low-level jet, a narrow river of air screaming into the storm a few thousand feet above the ground from the south and east. That allowed the howling winds to ride up the entire southeast and east coast of New England, whereas a more traditional offshore storm path would have restricted the strongest winds to Cape Cod and the Islands.
Parts of southeastern Massachusetts such as Fairhaven and Duxbury saw wind gusts to 88 mph and 80 mph, respectively. Even Boston’s Logan Airport saw a wind gust to 70 mph.
A secondary region of maximum winds developed on the backside of the low over Long Island, southwest Connecticut, and parts of New York in response to the rapid air pressure change in the storm’s wake. Stony Brook, on Long Island, saw a wind gust to 83 mph. Aptly named Breezy Point, in Queens, lived up to its name with a 76 mph wind gust.
In addition to the high winds, heavy rainfall doused some spots with a month’s worth of rainfall in less than 24 hours. Coventry, R.I., wound up with 4.13 inches, while Southwick, Mass., got 4.26 inches. Heavy rain also fell in Washington, Philadelphia, New York, Hartford, Conn., and Providence as the storm intensified.
Gusty winds and spotty showers, including some snow showers in the higher elevations of New England, are expected behind the departing low Thursday from the Mid-Atlantic through Maine before more tranquil weather builds in for the weekend.