What is Bomb cyclone?

Subject :Geography

Context:

The storm pummelling large swaths of the United States and Canada is what forecasters call a “bomb cyclone.” While this kind of storm is not exceedingly rare, this one is very strong, with high winds that are bringing heavy snow or rain to many areas.

What is Bomb Cyclone:

A bomb cyclone is a large, intense midlatitude storm that has low pressure at its centre, weather fronts and an array of associated weather, from blizzards to severe thunderstorms to heavy precipitation.

Reason for its formation:

Storms can form when a mass of low-pressure air meets a high-pressure mass.
The air flows from high pressure to low, creating winds.
In a Bomb cyclone, the pressure drops very rapidly in the low-pressure mass- by at least 24 millibars in 24 hours.
This quickly increases the pressure difference, or gradient, between the two air masses, making the winds stronger.
This process of rapid intensification has a name: bombogenesis.

Formation at the great lake region:

The conditions for the formation of a bomb cyclone had been met over the Great Lakes, where frigid Arctic air from the meandering polar vortex met very warm air to the east.
Air pressure dropped to at least 962 millibars, while elsewhere it was as high as 1,047 millibars.

How does a Bomb Cyclone differ from a Hurricane?

Hurricanes tend to form in tropical areas and are powered by warm seas. For this reason, they’re most common in summer or early fall, when seawater is warmest.
Bomb cyclones generally occur during colder months because cyclones occur due to cold and warm air meetings. During the summer, there’s generally not much cold air across the atmosphere; this means a bomb cyclone is much less likely to occur.
Hurricanes form in tropical waters, while bomb cyclones form over the northwestern Atlantic, northwestern Pacific and sometimes the Mediterranean Sea.