A massive winter storm called a “bomb cyclone” is set to hit portions of the United States on Wednesday, bringing dangerous heavy snow, flooding and thunderstorms to the central part of the country.

“This storm will be responsible for heavy rains, severe thunderstorms, isolated flooding, heavy snows, blizzard conditions and high winds over the next two days across large portions of the Central United States,” theNational Weather Servicesaid on Wednesday morning.

The bomb cyclone will mostly affect the Rockies, the Central and Northern Plains and the Upper Midwest. According to theNWS, blizzard warnings and winter storm warnings are in effect for parts of Colorado, Wyoming, North Dakota, South Dakota and Nebraska.

But what is a bomb cyclone?

According to theNational Oceanic and Atmospheric Administration, a bomb cyclone, or bombogenesis, occurs when the atmospheric pressure of a storm drops 24 millibars in less than 24 hours.

As pressure falls, the storm grows stronger and stronger, creating intense high winds and heavy snows.

A bomb cyclone usually happens when a cold air mass collides with a warm air mass, typically over a large body of water, so Wednesday’s storm could mark a rare inland bomb cyclone.

With the storm comes flight cancellations, school closures and concerns about safety.

As of Wednesday morning, there have been over 1,200 flights canceled in the United States, according toFlightAware, with the majority stemming from the Denver International Airport.

The NWS warned residents about safety, saying, “the heavy snow and visibility near zero will create extremely dangerous travel conditions, and power outages are also possible.”

The NWS in Boulder, Colorado, said that travel is “not recommended” and would be almost impossible at times due to high winds and whiteout conditions.

In addition,flood watcheshave been put in place for portions of Colorado, Kansas and southwest Nebraska, due to the combination of “heavy rainfall, snow melt and frozen and saturated soils” that could lead to heavy flooding in the area.

School districts across the region, including Denver Public Schools, are closed on Wednesday, citing “severe winter weather and road conditions.”

source: people.com