ORLANDO, Fla. – In recent years, terms like “bomb cyclone” and “polar vortex” have made their way into popular discourse, often attached to dramatic weather events.
While these terms may sound like media buzzwords, they are rooted in real meteorological phenomena.
A bomb cyclone, or a storm that undergoes bombogenesis, occurs when an area of low pressure experiences a dramatic drop in atmospheric pressure — 24 millibars or more within 24 hours. The rapid pressure decline signals an intensifying storm, comparable the rapid intensification seen in tropical cyclones.
The term may conjure images of destruction, but it refers specifically to the storm’s explosive development, not necessarily its damage potential.
Unlike tropical storms and hurricanes, which derive their energy from warm ocean waters, bomb cyclones are fueled by the temperature and pressure contrasts in the atmosphere. These mid-latitude cyclones are also known as baroclinic lows.
These contrasts are especially prominent during fall and winter, when frigid Arctic air meets warmer, moist air from the tropics.
While bombogenesis can happen anywhere in the world, it tends to be most common in regions with significant temperature and pressure contrasts. Here are a few hotspots:
- West Coast of North America: Bombogenesis frequently occurs off the southwest coast of Canada and the northwest United States, leading to powerful storms in the Pacific Northwest.
- Plains and Midwest: Bomb cyclones are often associated with blizzards that sweep through the interior of the U.S., creating hazardous winter conditions.
- East Coast (Nor’easters): The I-95 corridor and New England see some of the most dramatic examples, where cold Arctic air clashes with warmer air from the Gulf Stream.
These storms can bring a variety of extreme weather conditions, depending on their location and trajectory:
- Blizzards: Heavy snowfall, strong winds, and reduced visibility in the Midwest and Northeast.
- Severe Weather: Tornadoes, thunderstorms, and flooding rains in the southern U.S.
- Coastal Hazards: High winds, coastal flooding, and erosion along shorelines.