On Tuesday, the storm system that soaked southern New England and the New York tri-state area has been qualified as a ‘bomb cyclone’ due to its rapid intensification.
Some cities saw wind gusts between 60 and 100 mph overnight Tuesday, putting half a million customers across Massachusetts without power. These gusty winds also caused a 3-to-4 foot ocean surge in water above normally dry land.
The brunt of the storm hit New England Tuesday night, so conditions will ease as the week continues. However, extreme weather caused by bomb cyclones has packed quite the punch to the United States this week.
This article breaks down what a bomb cyclone is, what’s next for New England, and a recap of California’s atmospheric river impacts.
What’s a bomb cyclone?
The term ‘bomb cyclone’ has come up multiple times over the last few days. So what is a bomb cyclone?
A bomb cyclone is a storm that intensifies very rapidly, increasing 24 millibars (a unit of pressure) over 24 hours. They form when the air near Earth’s surface rises quickly in the atmosphere, triggering a sudden drop in barometric pressure. Wind spirals in at the base of the storm as air rises. As noted by NBC News, as long as the air continues to rise at the top of the storm faster than it can be replaced at the bottom, barometric pressure will continue to drop.
While bomb cyclones have many similar characteristics to hurricanes — gusty winds and heavy rain — they are not the same. Hurricanes tend to form in tropical areas and are triggered by warm seas.
Nor’easter Forecast: Boston + New England
Forecast by Tomorrow.io Meteorologist Jim Bishop
The October nor’easter continues to track northeast off the coast of New England, bringing strong north-northeast winds and rain. This nor’easter meets the criteria of a ‘bomb cyclone, with the pressure on Nantucket, Mass. having dropped 28 millibars over the past 24 hours. The last bomb cyclone occurred on October 17, 2019.
We officially have Bombogenesis (rapid intensification) with this Nor’Easter…
The pressure dropped 28 mb in 24 hours in Nantucket… last Bomb Cyclone was nearly 2 years ago. #WBZ #CBSBoston pic.twitter.com/NGA1Bmty9i
— Sarah Wroblewski (@sarahwroblewski) October 27, 2021
Peak wind gusts at Boston Logan reached 59 mph early Wednesday morning. Meanwhile, areas just to the southeast of Boston along the southeastern Massachusetts coast to Cape Cod have received Hurricane-force wind gusts, with the highest coastal gust of 87 mph at Scituate, Mass. at 4:30 a.m. The highest gust from this storm was in Edgartown, Mass., off the coast of Martha’s Vineyard at 4:31 a.m. at the Chappy Ferry dock with a gust of 94 mph!
As of 9 a.m., wind gusts in Boston were gradually beginning to decrease. However, 45-50 mph wind gusts may continue into midday, with gusts up to 40 mph remaining possible into the early evening.
Gusts to 60-70 mph are possible along Cape Cod through early Wednesday afternoon, with gusts along the Cape to 40-50 mph remaining possible tonight. The steady rain continues in Boston through midday before tapering into the afternoon and evening, persisting overnight along Cape Cod. As a result, pockets of moderate coastal flooding remain possible through the afternoon across Massachusetts, coinciding with this afternoon’s high tide, and beach erosion continues.
Bomb Cyclone Slams California
After months of wildfires and drought, a Level 5 out of 5 atmospheric river drenched California. This heavy precipitation helped alleviate the drought but did create dangerous mudflows and debris flow in areas devastated by fires.
— US StormWatch (@US_Stormwatch) October 25, 2021
Atmospheric rivers are narrow swaths of exceptionally moist air that can produce an excessive amount of precipitation.
The offshore system responsible for this atmospheric river set a record as an exceptionally intense bomb cyclone.