Most of the eastern United States is trapped in a deep freeze of near-record low temperatures thanks to an outbreak of Arctic air dipping south. And now they must prepare for an extremely strong winter storm otherwise known as a “bomb cyclone.”
Cyclone “bomb” is simply an ominous term for an explosively intensifying winter cyclone. These storms produce strong, damaging winds and are often accompanied by dangerous storm surges and heavy snow. “This can happen when a cold air mass collides with a warm air mass, such as air over warm ocean waters,” NOAA says. Note: a cyclone is a large air mass rotating around a center of low atmospheric pressure.
The term originates from a 1980 paper, “Synoptic-Dynamic Climatology of the ‘Bomb,’“written by the late Fred Sanders, a pioneer of weather forecasting at the Massachusetts Institute of Technology. Sanders describes a concept known as weather “bombs.”
Weather bombs are so-named for how quickly and powerfully they intensify. Bombogenesis is the process by which they develop. According to the National Oceanic and Atmospheric Administration (NOAA), bombogenesis “occurs when a midlatitude cyclone rapidly intensifies, dropping at least 24 millibars over 24 hours.”
The arctic air mass will remain entrenched over the eastern two thirds of the country through the end of the week with very cold temperatures and dangerously cold wind chills expected, per the National Weather Service.
Fred Sanders paper, “Synoptic-Dynamic Climatology of the ‘Bomb'” appeared in the October 1980 issue of Monthly Weather Journal.
Photo: Winter Storm Grayson from GFS Model at 24 hours (8 a.m. EST January 4th)