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

InnerSelf Market

Amazon

enafarzh-CNzh-TWdanltlfifrdeiwhihuiditjakomsnofaplptruesswsvthtrukurvi

follow InnerSelf on

facebook-icontwitter-iconrss-icon

 Get The Latest By Email

{emailcloak=off}

LATEST VIDEOS

To Reach Zero Emissions Government Must Address Hurdles Putting People Off Electric Cars
To Reach Zero Emissions Government Must Address Hurdles Putting People Off Electric Cars
by Swapnesh Masrani
Ambitious targets have been set by the UK and Scottish governments to become net-zero carbon economies by 2050 and 2045…
Spring Is Arriving Earlier Across The US, And That's Not Always Good News
Spring Is Arriving Earlier Across The US, And That's Not Always Good News
by Theresa Crimmins
Across much of the United States, a warming climate has advanced the arrival of spring. This year is no exception.
The Last Ice Age Tells Us Why We Need To Care About A 2℃ Change In Temperature
The Last Ice Age Tells Us Why We Need To Care About A 2℃ Change In Temperature
by Alan N Williams, et al
The latest report from the Intergovernmental Panel on Climate Change (IPCC) states that without a substantial decrease…
A Georgia Town Gets Half Of Its Electricity From President Jimmy Carter's Solar Farm
A Georgia Town Gets Half Of Its Electricity From President Jimmy Carter's Solar Farm
by Johnna Crider
Plains, Georgia, is a small town that is just south of Columbus, Macon, and Atlanta and north of Albany. It is the…
Majority of US Adults Believe Climate Change Is Most Important Issue Today
by American Psychological Association
As the effects of climate change become more evident, more than half of U.S. adults (56%) say climate change is the…
How These Three Financial Firms Could Change The Direction Of The Climate Crisis
How These Three Financial Firms Could Change The Direction Of The Climate Crisis
by Mangulina Jan Fichtner, et al
A silent revolution is happening in investing. It is a paradigm shift that will have a profound impact on corporations,…
Investing In Climate Change
by Goldman Sachs
“Top of Mind at Goldman Sachs” Podcast – In this episode, we dig into what may be the most important issue of our time:…
Climate Change: Briefings from Southern Africa
by SABC Digital News
Climate change affects us all, but it can be a confusing business. Three leading South African scientists who have…

LATEST ARTICLES

How Plants And Animals Share Response To Climate Change
How Plants And Animals Share Response To Climate Change
by Daniel Stolte
Plants and animals are remarkably similar in their responses to changing environmental conditions across the globe,…
Why Poorer Suburbs Are More At Risk In Warming Cities
Why Poorer Suburbs Are More At Risk In Warming Cities
by Jason Byrne and Tony Matthews
The many reasons for this include urban densification policies, climate change and social trends such as bigger houses…
Why A Better World Needs Better Economics
Why A Better World Needs Better Economics
by David Korten
Science warns us that the 2020s will be humanity’s last opportunity to save itself from a climate catastrophe.
A Second Us Dust Bowl Would Hit World Food Stocks
A Second Us Dust Bowl Would Hit World Food Stocks
by Tim Radford
When the US Great Plains are hit again by sustained drought, the world’s food stocks will feel the heat.
Rising Seas: To Keep Humans Safe, Let Nature Shape The Coast
Rising Seas: To Keep Humans Safe, Let Nature Shape The Coast
by Iris Möller
Even under the most conservative climate change scenarios, sea levels 30cm higher than at present seem all but certain…
To Reach Zero Emissions Government Must Address Hurdles Putting People Off Electric Cars
To Reach Zero Emissions Government Must Address Hurdles Putting People Off Electric Cars
by Swapnesh Masrani
Ambitious targets have been set by the UK and Scottish governments to become net-zero carbon economies by 2050 and 2045…
Huge Ecosystems Could Collapse In Less Than 50 Years
Huge Ecosystems Could Collapse In Less Than 50 Years
by John Dearing et al
We know that ecosystems under stress can reach a point where they rapidly collapse into something very different.
India Finally Takes Climate Crisis Seriously
India Finally Takes Climate Crisis Seriously
by Nivedita Khandekar
With financial losses and a heavy death toll from climate-related disasters constantly rising, India is at last…