Here's How the Weather `Bomb' That May Soak New York Began

(Bloomberg) -- It’s that time of year when weather forecasters start talking about “bombs.” In fact, one’s about to splash down on the U.S. East Coast, drenching the U.S. Mid-Atlantic to the Northeast.

These kinds of storms are born from a swirl of contrasting weather patterns. While hurricanes gain power from warm ocean waters, they get their punch from the sharp contrast between hot and cold air masses that form cyclones in a phenomenon known as bombogenesis -- or bomb for short.

Here's How the Weather `Bomb' That May Soak New York Began

In this case, warm, moist air is drifting up the East Coast from the Caribbean while a blast of cold air is set to descend across the Midwest into the South, pushing temperatures into the 30s Fahrenheit as far off as Dallas. The cold rolling south has sparked freeze and hard freeze warnings from Minnesota to Texas from Friday through Saturday, according to the National Weather Service. There could even be some snow in Minnesota and parts of Michigan’s Upper Peninsula.

With most crops mature and being harvested, the chill probably won’t be an issue for agriculture.

“It is that time of year when we start seeing more vigorous systems,” said Brian Hurley, a senior branch forecaster at the U.S. Weather Prediction Center in College Park, Maryland. “The threats are wind and rain, and it looks like a rainmaker.”

It will be a wind maker too, bringing a force to rival those of a hurricane. The upcoming one will bring winds from 35 to almost 60 miles (96 kilometers) an hour with gusts even higher, Hurley said. This raises the chances of flooding as the winds push up water along the shore.

Six Inches

Meanwhile, as much as 6 inches (15 centimeters) of rain will drop on the Hudson Valley and western New England in the next five days. An even wider swath from Ontario to North Carolina will see less, according to the Weather Prediction Center. The storm’s core is forecast to run right up the river into Quebec on Oct. 30.

Hurley said this system will have a deep well of both warm and cold to draw from, and computer forecast models are predicting it could get real strong, real fast.

It could even meet the specific definition of a weather bomb that Fred Sanders and John Gyakum created while at the Massachusetts Institute of Technology in 1980. Essentially any storm qualifies if its central barometric pressure drops by 24 millibars or more in 24 hours.

Such storms can undergo this massive change anywhere, but the chances enhance over water, Hurley said.

If this latest one had come just a few months from now, things could’ve been a lot worse for the eastern U.S. Because of an even deeper winter chill, the system could’ve easily dumped snow by the foot, halting cars, trains and planes in the cities in its path.

There’s still time for one of those, Hurley warned. We’re just “getting to that time of year.”

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