Bombogenisis: East Coast ‘bomb cyclone’ explodes next 24 hours

Meteorologists across the country are watching an intense low-pressure storm wind up along the East Coast Wednesday.

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NOAA GFS via tropical tidbits.

Bomb cyclone

The storm rapidly deepens in the next 24 hours and is expected to reach what we call "bomb cyclogenesis" intensity levels. Bomb cyclones are defined by a central pressure drop of at least 24 millibars in 24 hours.

Simply put, bomb cyclogenesis is the formation of an "extratropical area of low pressure in which the central barometric pressure drops at least 24 millibars in 24 hours."

Perfect storm

Atmospheric conditions are nearly perfect for driving this intense storm. There are three key ingredients that make for explosive bomb cyclones.

  • A warm "conveyor belt" of tropical moisture feeding the storm from the tropical Atlantic Ocean. This feeds massive amounts of heat energy and moisture into the front side of the system.

  • The massive arctic air mass behind the storm is driving a huge temperature contrast that feeds energy and boosts deepening.

The explosive deepening occurred as the large-scale baroclinicity across eastern North America increased in response to the arrival of very cold air behind the deepening northern trough.

Note the deep arctic air mass with subzero temperatures pooling behind the storm over the Great Lakes.

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GFS Forecast 2-meter surface temperatures Thursday morning via tropical tidbits.

  • A deep upper air wave is providing the dynamical forcing to deepen the system at the surface. Note the huge dip in the jet stream over the eastern U.S. by late Thursday.

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Winter hurricane

The storm's central pressure is expected to deepen Thursday to around 950 millibars. That's the equivalent of a Category 3 hurricane on the Saffir-Simpson Scale. This storm could rival Superstorm Sandy in terms of central pressure.

Unusual impacts

The deep arctic air pool behind this storm is driving some unusual impacts. Ice and snow are falling as far south as Georgia and Florida Wednesday.

I can't recall seeing winter storm warnings from the Jacksonville, Fla., National Weather Service office.

Hurricane force winds and coastal surge

The storm will cause coastal flooding along the east coast.

Huge wind-driven waves will roll in on top of all that storm surge.

Heavy snow

Heavy snow is forecast for Boston.

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Long Island also gets a significant shot of wind-driven snow.

Storm hammers Ireland

Meanwhile across the big pond, another storm has hit Ireland with 100 mph winds.

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