Governor Hochul Warns New Yorkers to Prepare for Winter Storm

The nor’easter about to tear up the U.S. East Coast with near-hurricane-force winds and fast-falling snow — as much as 10 inches of it in New York and more in Boston — is almost certain to intensify so rapidly that it will meet the definition of a bomb cyclone as it roars north. The technical term is “bombogenesis,” and it means the central pressure of a storm, a measure of its power, drops by at least 24 millibars in 24 hours.

The key ingredient of a weather bomb is the collision of cooler air with much warmer air, and that is on hand. A cold front from Canada dropped temperatures to a low of 17° Fahrenheit (-8° Celsius) in New York City’s Central Park overnight Wednesday into Thursday, while in the Atlantic Ocean, the water is warmer than normal. Cape May in New Jersey recorded a water temperature of 46°F, and in Georges Bank off Massachusetts, the ocean was 44.6°F, according to the National Data Buoy Center. Not exactly balmy, but enough to provide the grist for the bombogenesis mill.

Oceans are doing their part to stoke contrast with the cold spell over land. Oceans absorb more than 90% of the heat that greenhouse gases trap in the Earth. In 2021 the world’s oceans were hotter than ever previously measured, according to an international analysis published earlier this month. Even within that trend, the northwest Atlantic is a hotspot. The Gulf of Maine Research Institute reported this month that waters there are warming faster than 96% of the rest of global oceans.

Hurricanes usually get the headlines when it comes to rapid intensification, but more and more winter storms are experiencing this as well. Although on satellites the two kinds of storms look similar, their structure and where they draw their power is very different. Hurricanes draw strength from deep, warm ocean water that fuels thunderstorms, which are the building blocks of tropical systems.

But winter storms derive their power, in part, from wide contrasts in temperature. With sub-freezing temperatures over land and mild water just off the coast, this current nor’easter has the potential to be a beast, with snow falling so fast that plows probably won’t be able to keep up. Unlike hurricanes, which have their sharpest bite at their core, winter storms can spread their strength out across wider areas. Gusts of 70 miles per hour or more are expected to blast the New England coast.

Hurricane winds are defined as sustained winds of 74 miles per hour, so this winter storm will be close in its power.