Bomb cyclone: ​​What does the phenomenon behind the worst snowfalls in the US mean?

The Midwest is experiencing one of its worst winter storms of the season, with icy winds and heavy snowfall that have left thousands without electricity over the weekend. These climatic conditions are mainly due to the arrival of an extreme weather phenomenon: the so-called bomb cyclone or cyclonic bomb.

According to experts from the National Weather Service (NWS), this is a icy air flow that normally rotates over the North Polebut that sometimes moves south, joining with winter storms, which gives rise to heavy rain and snowfall.

In Iowa alone, there has been almost 25 centimeters of snowwhere, in addition, the 2024 electoral period begins this Monday, so the campaign events have had to be modified.

Meteorologists have called the bad weather a “life-threatening winter weather” and they predict continued snowfall from as far west as Oregon to as far east as Maine. Meanwhile, approximately 70 million people are under a winter weather alert.

What is a bomb cyclone and how dangerous can it be?

According to experts from NBCNewsa bomb cyclone “is a rapidly intensifying storm that forms when air near the Earth’s surface rises at high speed into the atmosphere, causing a sudden drop in barometric pressure”, that is, it drops at least 24 millibars (a pressure measure used in meteorology) in less than 24 hours.

Bomb cyclones form when a cold air mass It collides with a mass of hot air, generating a current that rotates until it reaches a cyclonic shape of enormous magnitude.

These are characterized by being powerful snow storms with heavy precipitation, as described by geographer Esther Mullens for The Conversation magazine, which have become increasingly violent and explosive as a consequence of the climate crisis.

One of the most frequent concerns about this phenomenon is its ability to train in just one daywhen in the past this process could take up to a week: “It only takes 24 hours from their formation for bomb cyclones to reach the maximum point of their power.. This behavior is known as bombogenesis,” explains an article in National Geographic.

The last bomb cyclone, recorded in January 2022, “buried” the states of New York, New Jersey, Massachusetts, Virginia, Maryland and Rhode Island, under 75 centimeters of snowas documented at the time by local media and news agencies.

Mullens warns that These phenomena have become unpredictable and “reveal the scope of the new climate dynamics and its adaptation.”