Account Login/Registration

Access KamloopsBCNow using your Facebook account, or by entering your information below.




Privacy Policy

What on earth is a 'bomb cyclone?'

The term, 'bomb cyclone' could just be the most bizarre word to kick off January 2018. It's being used at a rapid rate - almost comparable to the rapid drop in the low pressure system in eastern North America.

Many are using the word without any idea of what it means.

Bomb cyclones are intense winter storms that can blast as hard as a hurricane. The process that creates these bombs is known as bombogenesis.

"Any storm that deepens by 24 millibars or more in a 24 hour period is said to be undergoing explosive cyclogenesis, which is where the terminology for 'weather bomb' comes in," told Lisa West, meteorologist for Environment Canada to NowMedia.

"We've seen pressure drops of close to 40 mbs in a 24-hour period."

Meterologist, Alex Deakin, says weather bombs start in an area of low pressure - a region where pressure of the atmosphere at sea level is lower than the surrounding area.

But low pressure systems are common, so what is special about this particular low pressure system that's wreaking havoc in eastern North America?

When there's a drop in atmospheric pressure, it allows the storm system to pick up more air and gain strength. When it drops rapidly - it's considered a bomb.

The current weather bomb is actually called winter storm Grayson.

Atlantic Canada residents have warnings for winter storms in areas where 25 to 45 centimeteres of snow could fall, as well as rainfall warnings, storm surge warnings and severe wind warnings.

Because of the frozen ground surface, the ground is unable to absorb the rainfall, which can actually make the rain freeze on contact, according to West. According to West, the cold air feeding into the low pressure system is what's causing these storms to bring snow instead of the usual rain.

This video of snow falling in South Carolina is the perfect example of that cold air mixing with the low pressure system.

"In this case, we had the Arctic air mass in place already right across Canada and down through the states. So there was lots of cold air there to begin with, and as the low pressure systems moved up, it's pulled even more cold air down into this system, which has helped keep precipitation in the form of snow for many of the regions."

For weather alerts across Canada, go to Environment Canada.

Send your news tips, photos and videos to [email protected]
Click here, to have your voice heard.