Concern grows with warnings from the generation of a powerful “bomb cyclone” that will not only bring heavy rain to the states of California, Washington y Oregonbut also has an unusual name that refers to a meteorological term.
The word “bomb cyclone” serves to define a natural phenomenon known as “bombogenesis”which in turn refers to the rapid strengthening of a storm in less than a day, that is, when a low pressure area experiences a rapid decrease in its barometric pressure in a period of 24 hours, thus triggering a system of hurricane-force winds, torrential rains or intense snowfall, according to information from AccuWeather.
Unlike tropical cyclones, these systems are not limited to warm waters, and can form in both oceans and land. The National Oceanic and Atmospheric Administration (NOAA) details that the intensification necessary to be considered “bombogenesis” will vary depending on latitude.
At 60 degrees latitude, the drop is at least 24 millibars (24 hectopascals) in a day, while in the city of New Yorkthe required pressure drop is “approximately” 17.8 millibars in 24 hours, according to NOAA.
“Bombogenesis can occur when a cold air mass collides with a warm air mass, such as air over warm ocean waters. It is popularly known as a bomb cyclone,” detailed the atmospheric administration authorities.
The basic principle behind its operation, according to AccuWeatheris the interaction between air masses of extreme temperatures. In the northern hemisphere, these phenomena rotate counterclockwise, while in the southern hemisphere they rotate counterclockwise.
This movement is driven by the Earth’s rotation and generates winds that converge towards the center of the storm. The strength of a bomb cyclone lies not only in its winds, but also in its precipitation. As the air rises and cools, moisture condenses, triggering heavy rain or snowfall.
Bombogenesis is not a recent phenomenon, and several storms throughout history have illustrated its impressive destructive power. A prominent example, and cited by the media specialized in climate, is the Supertormenta de 1993also known as “The Storm of the Century”, which occurred on March 12 and 13 of that year.
In just 24 hours, this meteorological phenomenon intensified its strength by decreasing its barometric pressure from 996 millibars to 963 millibars, a change of almost 33 units. This extreme event affected large regions of the United States.
Other notable cases include Hurricane Charley in 2004 and the Hurricane Wilma in 2005, both in the Caribbean, where bombogenesis contributed to its rapid strengthening and devastating impacts.
More recently, the Storm Denniswhich affected the United Kingdom on February 14, 2020, showed how this phenomenon can also occur in Europe, causing flooding and strong winds.
Within the states that will be affected by the bomb cyclone this Wednesday, flash flooding and power outages can be expected, in addition to falling trees and property damage, according to reports. The Associated Press.
The north of the state, which will be the target of the phenomenon from Wednesday to Friday, could receive up to between 5 and 10 centimeters of rain per day, according to information from Fox Weather.
The above forced the Meteorological Prediction Center to issue flash flood zones.
The southwest of Oregonclose to the coast, between 10 and 18 centimeters of rain were forecast, with up to 25 centimeters in other areas, as stated by meteorologist Richard Bann.
