One of the strongest coastal storms in recent memory is an impressive coda to a marathon winter across eastern North America.
The storm has now officially breached the definition of a “double bomb,” exploding in intensity by more than 48 millibars in 24 hours.
According to my analysis, the storm deepened from 1,008 millibars to 958 millibars in exactly 24 hours, between 9 a.m. Tuesday and 9 a.m. Wednesday, Eastern time, per the high-resolution NAM model. Even more impressively, the storm’s central pressure dropped by 24 millibars in just a six-hour period between midnight and 6 a.m. Wednesday—a deepening rate four times that necessary for a “bomb.”
Such an intensification rate has rarely occurred outside of tropical cyclones and is almost unprecedented for a winter storm.
The result is meteorological eye-candy for those not in the direct path:
Throughout its forecast, the storm has drawn comparisons to the Superstorm of 1993 and other infamous coastal Atlantic storms. It has delivered.
The storm—now the most intense near the East Coast since Superstorm Sandy—will narrowly miss a full-scale impact in the United States, but is still bringing blizzard conditions to limited sections of the coast. As of early Wednesday morning, winds on Nantucket Island 100 miles southeast of Boston were gusting near hurricane force under whiteout conditions. Similar conditions are expected across remote sections of coastal Maine later Wednesday.
In Canada, the storm will display its full fury: Meteorologists in Nova Scotia are already comparing it to “White Juan”—an infamous blizzard that buried the Halifax area under nearly three feet of snow in February 2004.
Later on Wednesday, as the storm makes its closest approach to Canada, forecasters are anticipating winds near hurricane force with gusts much higher just offshore. Snow totals could top two feet, and much of the region is essentially shut down.
Offshore, the storm has exploded with winds and waves rarely seen outside the strongest hurricanes.
A partial merging of all three strands of the jet stream—subtropical, polar, and arctic—is partly responsible for the tremendous energy of the coming storm. That has produced off-the-charts rates of intensification, which in turn is producing off-the-charts wind speeds, wave heights, and low pressure, especially for this time of year.
In fact, one meteorologist estimated that one measure of this storm’s ferocity—Integrated Kinetic Energy—could wind up being four times more powerful than Superstorm Sandy. That measurement is typically used as a way to combine both the size and strength of a storm into a single number. Thankfully, winter storms transfer that power to the surface less efficiently than tropical storms due to the lack of a compact inner core of deep thunderstorms, and most of this storm’s energy will be expelled over the open ocean, not squarely directly at the New Jersey coast, like in Sandy.
Still, had the storm’s track shifted just 150 or so miles to the west, places like New York City and Boston would have been measuring snow accumulations in feet, not inches. Instead, for most of the eastern United States, the storm’s impact was limited to yet another unseasonably cold day.
Freeze warnings blanketed the Deep South from Louisiana to the Carolinas, where temperatures lingered below freezing for several hours—long enough to push the reset button on any early spring garden plans. If you’re bundled up in Atlanta (as you’ve likely been so often during this brutal winter), be thankful you’re not in northern Maine: Tuesday morning’s low in Bangor was zero degrees Fahrenheit. According to the National Weather Service, it’s never been that cold this late in the season.
Later on Tuesday, snow covered the spring blossoms in Washington, D.C., setting a more than 100-year-old daily record as the impressive storm began to take shape off the coast. A unique temperature record was set there, too: Tuesday’s high of 33 degrees at Dulles Airport was the coldest high temperature this late in March in the D.C. area, according to the Washington Post’s Capital Weather Gang.
By the time the snowy hurricane-like beast of nature pushes away on Wednesday, there will still be lingering cold air to deal with. As the bearer of bad news for the umpteenth time over the last few months, NOAA Climate Prediction Center has below normal temperatures across the East through at least the first week of April.