Today's Editorial

Today's Editorial - 06 January 2023

What is a ‘bomb cyclone’?

Source: By Henry Fountain: New York Times

The storm pummelling large swaths of the United States and Canada is what forecasters call 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 can 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, making the winds stronger. This process of rapid intensification has a name: bombogenesis.

As the winds blow, the rotation of the Earth creates a cyclonic effect. The direction is counterclockwise in the Northern Hemisphere (when viewed from above).

John Moore, a meteorologist and spokesperson for the National Weather Service, said conditions for a bomb cyclone had been met over the Great Lakes, where frigid Arctic air from the meandering polar vortex met very warm air to the east. Air pressure dropped to at least 962 millibars, while elsewhere it was as high as 1,047 millibars. “It’s a really sharp gradient,” he said.

As the area where the two air masses meet, called the Arctic front, moves northward and eastward, conditions for bombogenesis should continue moving as well, Moore said.

But as the Arctic air spreads over most of the country it will eventually warm, reducing the pressure difference. The storm will dissipate. And forecasts call for above-average temperatures across most of the country next week, he said.

An intense blizzard (or snowstorm) is wreaking havoc across the United States and Canada, with more than 30 people confirmed dead so far in the US, and four people dead in Canada after a road accident on an icy path.

At one of the most important periods for travel and tourism around the world, and especially in these two countries as families come together to celebrate the holiday season, life has been interrupted.

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 22 December 2022 that “a blast of Arctic air will plunge south and help trigger a powerful blizzard that will churn through the central and eastern US.”

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 on 25 December 2022, 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. They call 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.

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.