How an October snowstorm shut down New England in 2011, exposing power grid
The violent snapping and crashing of tree limbs echoed off a deep blanket of snow all night, like gunshots ringing through the forests of southern New England. Those trees still standing slouched precariously amid the weight of wet, heavy snow pressed against lingering autumn foliage.
As trees resigned to gravity, power outages mounted, ultimately leaving more than 3 million people in the dark. Occurring one decade ago, it was one of the largest grid failures in U.S. history.
The Northeast is accustomed to powerful coastal storms, but the damage from the 2011 Halloween nor’easter, dubbed “Snowtober,” raised the bar for fall tempests. Unloading feet of October snow, it smashed century-old records while revealing the fragility of the region’s power grid.
The region’s grid has continued to show weaknesses in the face of extreme weather in the decade since.
Inside the storm
Not unlike this year, 2011’s autumn was warm, and the foliage remained remarkably intact through late October in southern New England. By Oct. 27, as a strong cold front slid across the Northeast, leaves had yet to fully fall across much of Connecticut, Massachusetts and New York.
As the late October cold front swept through New England, the weather pattern suddenly turned wintry. The jet stream, which separates cold air from warm air thousands of feet above ground, took a dive into the central U.S. and Great Lakes, opening a path for energetic storms from central Canada to slide toward the Northeast.
One of these storms, enthusiastic but moisture-starved, leaped toward the Atlantic coast from Alberta late on Oct. 28. As it approached the Northeast, so too did a broad zone of low pressure offshore the Carolinas. As the two combined, cold air from the Canadian storm was dragged south while deep Atlantic moisture was drawn north. And a formidable nor’easter was born.
Snowflakes began to fall. At first they melted before hitting the ground in many areas, turning to a cold rain. But as frigid Canadian air was drawn closer to the coast, the raindrops changed to snow from the hills toward the shoreline.
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The flakes were fat, wet and dense due to temperatures hovering within a few degrees of freezing. Closer to the Interstate 95 corridor, from New York to Boston, temperatures were only low enough for a few inches to accumulate. But the snow was like cement and a load to shovel. Further north and west, across a stripe of the interior Northeast, the pasty snow fell on vast swaths of forest. Where leaves remained on trees, the stress of the heavy snow on limbs and trunks grew immense.
By Oct. 29, inches turned to feet as band after band of snow rotated through the interior Northeast. In the corridor from northeast Pennsylvania through east-central Massachusetts, limb after limb shattered from the snow’s heft.
Amounts included:
- 2.9 inches in New York City’s Central Park
- 12.3 inches in Hartford, Conn.
- 14.6 inches in Worcester, Mass.
- 19 inches in West Milford, N.J.
- 22.5 inches in Concord, N.H.
- 32 inches in Peru, Mass.
The power problem
Trees fall often in the expansive forests of the Northeast. But as more and more people have made these forests their home, and as the woods themselves rebound from centuries of logging, tree-fall events have increasingly wrought havoc.
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As the night of Oct. 29 wore on, every one of the constant snaps that echoed across New England indicated a limb or tree losing the fight against the snow. Many also represented a battle lost between the power grid and the environment it was built within, as these falling trees severed countless power lines.
The extent of power loss was tremendous and, for many, unprecedented. Nearly 1 million people in Connecticut alone lost electricity, the worst power outage on record for the state, breaking a record set only two months earlier during Tropical Storm Irene.
For hundreds of thousands of the region’s residents, tree destruction — and resulting power failure — was so complete that it took over a week for the lights to turn back on.
Ryan Hanrahan, chief meteorologist for the NBC television affiliate in Hartford, says the power grid vulnerabilities exposed by the 2011 nor’easter are still present. In an interview, he said that while companies are now somewhat better prepared than they were a decade ago, recent storms have demonstrated a still-fragile electrical distribution system.
“The power grid in New England remains uniquely vulnerable to extreme weather events,” he said. “As we saw in the October snowstorm of 2011 and even more recently during Tropical Storm Isaias, the power grid is quite vulnerable given how many trees line every mile of distribution line in the state.”
In August 2020, winds around 60 mph from Isaias knocked down thousands of trees. More than 3.6 million people in New Jersey, New York and Connecticut lost power for days.
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Even this week’s “bomb cyclone,” in which wind gusts over 60 mph were mostly confined to coastal areas, cut power to more than 600,000 customers in New England.
In Connecticut, Isaias was one of three tropical cyclones in the past decade that have produced power outages nearly as numerous and long-lasting as the 2011 snowstorm, alongside Sandy and Irene. While all three brought winds no stronger than tropical-storm-force, gusts were sufficient to snap enough tree limbs to cripple the frail grid. The region’s abysmal track record with relatively weak systems is problematic, Hanrahan said.
“I’m worried about what happens when a significant hurricane hits,” he said.
The region is currently experiencing an unusual hurricane drought, but storms far stronger than Isaias have hit New England in the past century. When the next one does eventually strike, Hanrahan fears, results could be catastrophic. “The outages would last for months.”
Feuerstein is a college junior studying meteorology at Cornell University.
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