What is a bomb cyclone, and will it bring Philadelphia snow this weekend?
This weekend, a powerful winter storm known as a bomb cyclone will develop off the South Carolina coast and travel north along the East Coast. It will deliver heavy snow for the Carolina and Virginia coastlines.
After that, the storm will either turn farther out to sea, just clipping the Jersey Shore, Delaware beaches, and South Jersey with snow, or it will track closer to the Shore, bringing heavy snow to South Jersey, the Jersey Shore, Delaware and possibly Philadelphia.
The two long-range models, GFS (the American) and ECMWF (the European), have been bouncing back and forth with these two tracks. A final track will become clearer by Saturday morning.
Even if the storm stays farther offshore, strong winds will be possible over the weekend.
What is a bomb cyclone?
Every year, a handful of fall and winter storms undergo what is known as bombogenesis, becoming bomb cyclones.
These storms begin as minor or average storms and then go through a rapid, explosive intensification, delivering heavy snow, blizzards, thundersnow, coastal flooding and flooding rains.
Their impacts include widespread power outages, coastal erosion, tree damage, and structural damage due to near hurricane force winds that reach 74 mph, and lead to the nickname "Winter Hurricane."
Ingredients for bombogenesis include:
- A non-tropical cyclone (winter storm)
- A clash between an Arctic air mass and a warmer and moist ocean air mass
- A rapid, enormous drop in the storm's central pressure of 24 mb or more in a 24-hour period
Bomb cyclones are possible year-round, but they are most common along the eastern seaboard of the United States during winter and early spring. Extreme nor'easters are usually bomb cyclones.
