Bomb Cyclone explained: Why this powerful winter storm is paralysing the US

Heavy snow and strong winds are pushing across the northeastern United States as a powerful winter storm intensifies offshore. Forecasters say the system now meets the definition of a bomb cyclone after a rapid drop in central pressure over 24 hours. Blizzard warnings are in place for major cities along the I-95 corridor, including New York City, Boston and Philadelphia. Snowfall rates of up to three inches per hour have been recorded in some areas, with gusts reaching 60 miles per hour. According to FOX News, more than 250,000 customers are without electricity across the Northeast and Mid-Atlantic, with New Jersey reporting the highest number of outages. Travel conditions are deteriorating as whiteout conditions reduce visibility and snow continues to accumulate.

Bombogenesis causes severe winter weather in the US

Meteorologists classify the system as a bomb cyclone because its central pressure fell rapidly to around 988 millibars. This process, known as bombogenesis, happens when a midlatitude cyclone strengthens quickly within 24 hours.




The required pressure drop depends on the location. Near the latitude of New York City, a fall of roughly 17 to 18 millibars in a day is enough. Further north, the benchmark is higher. The current storm has met that threshold.

What is a bomb cyclone, and why is it powerful

A bomb cyclone is a storm that suddenly gets much stronger. It can bring heavy snow, strong winds, rain, and even flooding. The term comes from “bombogenesis,” which happens when a storm’s pressure drops quickly usually 24 millibars in a day. The faster the pressure falls, the stronger the storm can get.

As reported by NOAA, for instance, at 60 degrees latitude, a storm’s pressure must drop by 24 millibars within 24 hours. At around 40 degrees latitude which includes New York City; a storm only needs to strengthen by 17.8 millibars over the same period.

How a bomb cyclone forms

These storms usually start when cold air moves over warmer ocean water. The difference in temperature makes the air unstable, and warm, moist air rises. This gives the storm energy and moisture, helping it grow and lowering its pressure.

As the storm strengthens, winds pick up, and it can bring heavy snow or rain, depending on the local weather. Bomb cyclones mostly happen in mid-latitude areas and are called extratropical storms, not hurricanes.

Blizzard conditions disrupt major cities

Blizzard warnings cover parts of New York, Massachusetts and Pennsylvania. Snow is falling heavily at times, with steady winds lifting and blowing it across roads and rail lines.

Air travel has been disrupted and some train services have been suspended. Local authorities have urged residents to stay indoors unless travel is necessary. Coastal areas are also seeing rough surf and minor flooding in exposed spots.

Power outages rise as wind gusts reach 60 miles per hour

Utility companies report widespread outages, particularly in New Jersey, where more than 100,000 customers are without power. Wet snow and strong gusts are bringing down tree branches and power lines. Crews are working in difficult conditions. Restoration may take time as snow continues to fall and winds remain strong. Forecasters expect the storm to move gradually northeast, though cold air is likely to linger after the heaviest snow ends.