Bomb cyclone

Why in the news?

The United States is bracing for heavy rains as a powerful "bomb cyclone" heads toward the country's west coast.

Key points:

• According to weather experts, the bomb cyclone will combine with a Category 5 atmospheric river to make it the most powerful storm of its kind.
• The storm is likely to dump about 8 trillion gallons of water.
• It will not only bring heavy rains but also hurricane-force winds.
• The epicenter of the stormy conditions is likely to be around Vancouver Island in Canada to the Oregon-California border.
• It can potentially cause widespread destruction in several states:
  • Widespread flooding
  • Devastating landslides
  • Large-scale destruction of infrastructure

What is a 'bomb cyclone'?

• This cyclone is an intense mid-latitude cyclone with low air pressure at its center.
• The term comes from the meteorological term "bombogenesis."
  • Bombogenesis occurs when a mid-latitude cyclone located between the tropics and polar regions strengthens dramatically in 24 hours.
• This intensification is marked by a sharp drop in atmospheric pressure (at least 24 millibars in a day).
• These cyclones form when warm, moist air collides with cold Arctic air, creating an unstable mixture that promotes explosive storm development.
• For this reason, meteorologists in the 1980s coined the term "bomb cyclone," drawing a comparison between the rapid intensification of a hurricane and the explosion of a bomb.