Unprecedented ‘bomb cyclone’ in US, Canada: What is happening, and why?

Why is this happening, and what might the next few days bring? We explain.

So what does “zero mile” visibility look like? Well, here’s a spectacular view of our parking lot near the airport. Yes, there are cars parked just a few feet away.

We don’t even want to be parked in it, you *definitely* don’t want to be driving in it. Seriously. https://t.co/ikpMJTnoU7 pic.twitter.com/px5jmVFLIe

— NWS Buffalo (@NWSBUFFALO) December 23, 2022

What is happening with the blizzard?

According to an AP report, the scope of the storm has been nearly “unprecedented”, stretching from the Great Lakes near Canada to the Rio Grande along the border with Mexico. About 60% of the US population faced some sort of winter weather advisory or warning, and temperatures plummeted drastically below normal in major areas of the country, the National Weather Service said.

NASA’ Earth Observatory had shown on December 22 that “a blast of Arctic air will plunge south and help trigger a powerful blizzard that will churn through the central and eastern US.”

(Source: NASA Earth Observatory)

New York Governor Kathy Hochul called it an “epic, once-in-a-lifetime” weather disaster that ranked as the fiercest winter storm to hit the greater Buffalo area in New York since a 1977 blizzard that killed nearly 30 people. At present, thousands of flights have been delayed or cancelled.

As the temperature has continued dipping, many houses are without heat and lights. In New York, about 34,000 households were still without power Sunday, and while power is now being restored, thousands of households are still cold and dark.

Migrants from Mexico and Central America attempting to reach the United States are also facing issues as a result, with authorities struggling to provide them with shelter.

What is a “bomb cyclone”?

Forecasters have termed the blizzard as different from the usual weather events and called it a “bomb cyclone.” While this kind of storm is not exceedingly rare, this one is very strong, with high winds that are bringing heavy snow or rain to many areas.

Storms form when a mass of low-pressure air meets a high-pressure mass. The air flows from high pressure to low, creating winds.

What defines a bomb cyclone is how rapidly the pressure drops in the low-pressure mass — by at least 24 millibars in 24 hours. This quickly increases the pressure difference, or gradient, between the two air masses, therefore making the winds stronger. This process of rapid intensification has an even more ferocious-sounding name: bombogenesis.

John Moore, a meteorologist and spokesperson for the National Weather Service, explained in an article in The New York Times that as the area where the two air masses meet moves northward and eastward, conditions for bombogenesis should continue moving as well.

What are the precautions being advised so far?

But as the Arctic air spreads over most of the country it will eventually warm, reducing the pressure difference, so the storm will eventually dissipate. Forecasts are indeed calling for above-average temperatures across most of the country next week, Moore said.

We are asking everyone to stay indoors and avoid travel today. If you must get on the road, please remember the following:
➡️Have a full tank of gas
➡️Prepare a vehicle kit with blankets & supplies
➡️Go slowly, use caution and visit https://t.co/db3wI5AOJH for conditions pic.twitter.com/AYkkEQgh1s

— Governor Andy Beshear (@GovAndyBeshear) December 23, 2022

Till then, those who will be travelling by road will need to exercise particular caution, as visibility will be affected. Governor Hochul said, “I’m asking everyone to stay off the roads this evening as conditions will worsen when temperatures drop across the state later today. Bundle up, stay indoors, and stay safe this weekend.”

Those indoors have also been told to maintain safety precautions, such as charging electronic devices and keeping torches ready. Apart from wearing the appropriate layers of clothing, it was also advised that those working outside keep taking breaks to avoid exertion or health issues.