Why in news?
In January 2026 meteorological agencies in the United States and Europe warned of “bomb cyclone” conditions as a rapidly intensifying winter storm brought hurricane‑force winds, heavy snow and coastal flooding. The term drew public attention and prompted questions about what distinguishes these storms from hurricanes.
Background
A bomb cyclone is not a tropical hurricane but a powerful mid‑latitude low‑pressure system that undergoes explosive cyclogenesis. This occurs when the storm’s central pressure drops by at least 24 millibars in 24 hours, causing the system to rapidly strengthen. Several ingredients contribute to their formation:
- Temperature contrast: A strong difference between cold continental air and warm ocean waters fuels intense convection.
- Jet stream dynamics: The polar jet stream carries pockets of high vorticity that can spin up surface lows.
- Moisture supply: Warm ocean surfaces provide abundant moisture, which releases latent heat as it condenses, further deepening the storm.
Characteristics
- Rapid intensification: Pressure falls quickly, leading to a steep pressure gradient and extremely strong winds, sometimes exceeding 120 km/h.
- Heavy precipitation: Depending on location and temperature, bomb cyclones can deliver blinding snow, freezing rain or torrential downpours.
- Coastal hazards: On the U.S. East Coast they can generate storm surges and coastal flooding; on the West Coast they drive large waves and heavy mountain snow.
- Seasonality: These storms typically occur in late autumn and winter when sea‑surface temperatures remain relatively warm compared with cold continental air masses.
Distinction from hurricanes
Unlike tropical cyclones—which derive energy from warm ocean waters and have a warm core—bomb cyclones are extratropical systems fed by temperature contrasts and the jet stream. Their wind fields are broader but less organised, and they often impact larger geographic areas. Nevertheless, their winds and precipitation can rival hurricane intensity.
Source: The Indian Express
