When does a winter storm become a bomb cyclone?

When does a winter storm become a bomb cyclone?

Blizzards in March, when our thoughts start turning to spring, are never good news. But warnings of “bomb cyclones” take the intensity to a new level. What does this ominous term, and related jargon like “bombogenesis,” tell us about the storm pounding states from Texas to Minnesota this week?

Let’s begin with the easy part: A cyclone – specifically, an extratropical cyclone, to distinguish from its tropical counterpart – is a large weather system with low pressure at the center and precipitation along cold and warm fronts. These storms are very common in autumn, winter and spring in the middle latitudes. The central and eastern United States typically see several over the course of a cool season.

What, then, distinguishes a “bomb” from a run-of-the-mill cyclone? The term was coined by famed meteorologists Fred Sanders and John Gyakum in a 1980 paper, and was inspired by the work of the Swedish meteorological pioneer Tor Bergeron. It describes a cyclone in which the central pressure drops very rapidly – an average of 24 millibars in 24 hours, at Bergeron’s latitude of 60 degrees north (the value becomes a bit smaller at lower latitudes). This is a lot when considering that variations of 10 or 15 millibars are typical over the course of any given week.

“Given their explosive development, it was an easy path to take to just call these systems ‘bombs,’ Gyakum said in an interview last year.

Wind speed is a function of the "pressure gradient” – the magnitude of the change from higher atmospheric pressure outside the cyclone to low pressure at its center, as well as how quickly the pressure changes over time. This means that a storm that rapidly develops an intense low-pressure region will have persistent strong winds.

Bomb cyclones are quite common over warm ocean currents, such as the Gulf Stream off the east coast of North America or the Kuroshio east of Japan. In both regions they draw energy from both the typical north-to-south variation in temperature and the warm water. Over land, although cyclones are common, it is very unusual to see them intensify so rapidly.

This week’s storm over the central U.S. appears likely to approach or even exceed the criterion for a “bomb.” It may also be among the lowest pressures on record for the Great Plains. But whether or not these specific standards end up being met is really only relevant for meteorological studies.

What is important is that the storm will develop quickly, and that it will produce a powerful combination of snow and wind over the Plains of Colorado, Wyoming, Nebraska and the Dakotas – a true blizzard. Conditions will change rapidly from warm and calm to heavy snow with intense wind gusts In the southern Plains, rain and thunderstorms – also with strong winds – are the main threat.

People in the storm’s path can expect major travel disruptions, potential power outages and risks to livestock. On the positive side, the attention that storms like this now receive, several days before they even develop, shows how much progress has been made in weather forecasting in recent decades, and how people can now be much better prepared for their impacts.

Authors: Russ Schumacher, Associate Professor of Atmospheric Science and Colorado State Climatologist, Colorado State University

This Article Originally Appeared On The Conversation

Related Books

enafarzh-CNzh-TWdanltlfifrdeiwhihuiditjakomsnofaplptruesswsvthtrukurvi

follow InnerSelf on

facebook-icontwitter-iconrss-icon

 Get The Latest By Email

{emailcloak=off}

LATEST VIDEOS

Did Scientists Get Climate Change Wrong?
by Sabine Hossenfelder
Interview with Prof Tim Palmer from the University of Oxford.
The New Normal: Climate Change Poses Challenges For Minnesota Farmers
by KMSP-TV Minneapolis-St. Paul
Spring brought a deluge of rain in southern Minnesota and it never seemed to stop.
Report: Today's Kids' Health Will Be Imperiled by Climate Change
by VOA News
An international report from researchers at 35 institutions says climate change will threaten the health and quality of…
How Supercharged Trash Gas Could Produce More Green Energy
by InnerSelf Staff
Synthetic compounds called “siloxanes” from everyday products like shampoo and motor oil are finding their way into…
300 Million Face Severe Risk of Climate-Fueled Coastal Flooding by 2050
by Democracy Now!
As a shocking new report finds that many coastal cities will be flooded by rising sea levels by 2050, Chile’s President…
Climate Warning: California Continues To Burn, Data Estimates Of Global Flooding
by MSNBC
Ben Strauss, CEO and Chief Scientist of Climate Central joins MTP Daily to discuss alarming new information about…
Stanford Climate Solutions
by Stanford
Climate change has brought us to a defining moment in human history.
Buying Renewable Energy From Your Neighbor
by NBC News
Brooklyn Microgrid, a project of parent company LO3 Energy, is looking to disrupt the more than 100-year-old energy…

LATEST ARTICLES

Why We Can't Yet Predict Where Millions Of Climate Refugees Will Go
Why We Can't Yet Predict Where Millions Of Climate Refugees Will Go
by Derek Groen and Diana Suleimenova
In the near future, global warming is expected to create millions of climate refugees, and individuals and…
A Hot And Dry Australian Summer Means Heatwaves And Fire Risk Ahead
A Hot And Dry Australian Summer Means Heatwaves And Fire Risk Ahead
by Catherine Ganter and Andrew B. Watkins
Summer is likely to start off hot and dry, according to the Bureau of Meteorology’s summer outlook, released today.
Technologies To Manage Climate Change Already Exist
Technologies To Manage Climate Change Already Exist
by Andreas Busch
When it comes to tackling climate change the UK is still taking baby steps. A lot more needs to be done – and fast – to…
Why Our Children And Grandchildren Await A Radioactive Legacy
Why Our Children And Grandchildren Await A Radioactive Legacy
by Paul Brown
We are leaving our children a radioactive legacy, the lethal waste that current governments still cannot make safe.
UN Report Warns Only Rapid and Transformational Action Can Stave Off Global Climate Disaster
UN Report Warns Only Rapid and Transformational Action Can Stave Off Global Climate Disaster
by Jake Johnson
Failure to heed these warnings and take drastic action to reverse emissions means we will continue to witness deadly…
How The Low-carbon Transition Is Disrupting Fossil Fuel Politics
How The Low-carbon Transition Is Disrupting Fossil Fuel Politics
by Cara Daggett
As the Trump administration works to weaken regulations on fossil fuel production and use, a larger struggle is playing…
Why Fossil Fuel Divestment Will Increase Carbon Emissions, Not Lower Them
Why Fossil Fuel Divestment Will Increase Carbon Emissions, Not Lower Them
by Stefan Andreasson
A global campaign encouraging individuals, organisations and institutional investors to sell off investments in fossil…
Hothouse Earth: Here's What The Science Actually Says
Hothouse Earth: Here's What The Science Actually Says
by Richard Betts
A new scientific paper proposing a scenario of unstoppable climate change has gone viral, thanks to its evocative…