The term “weather bomb” has been making the rounds lately, appearing on the front page of newspapers and the top of television news cycles. Despite this phrase only recently entering household conversation, the meteorological definition of the “bomb” has been around for decades.
When did the term come about, and how was “bomb” selected?
It came from a paper we published in 1980. The title was “Synoptic-Dynamic Climatology of the ‘Bomb.’ ” I was a graduate student at the time [at MIT], and my adviser, who was the lead author, Frederick Sanders, actually coined the term. He had quite a bit of experience making forecasts for cyclones in the North Atlantic that were developing very rapidly. Oftentimes, we’d even say explosively. Given their explosive development, it was an easy path to take to just call these systems “bombs.”
What does a storm have to do to be classified as a “bomb”?
We defined it as a series of pressure falls that occur in a rapidly developing cyclone. The central pressure of the storm has to drop at the rate of one millibar per hour for at least 24 hours.
What first brought your attention to this phenomenon?
We noticed a tendency for storms in the northern Atlantic and Pacific to sometimes intensify quickly during the fall and winter months. What really brought attention to these storms was a rare summertime storm in 1979. The storm bombed out and impacted the Fastnet yacht race in the United Kingdom. It caused widespread damage and a number of casualties, and elevated these sorts of storms to international attention.”
What role did your paper have in the science of forecasting these storms?
One of the reasons we published this paper was that these explosively developing cyclones were most prevalent during the wintertime — and the winds themselves tended to be of hurricane force. Impacts of these cases were often comparable to those of hurricanes. But many people would mistakenly let their guard down once hurricane season was over. This happened a lot with marine and coastal interests. Our goal was to help raise awareness that damaging ocean storms don’t just happen during the summer.
Did the term “bomb” take off immediately after the paper was published?
The paper helped to launch into public perception a little bit more. It mainly served to raise the awareness of scientists, which was most important since they are the stakeholders, so to speak. That spawned a lot of important research. At the time, forecasting for these systems was poor. The Presidents’ Day storm in ’79 dropped record-shattering snow on D.C., for instance, and it was really poorly forecast. Thanks to the work that’s been done since, prediction has improved phenomenally. And I think the term has helped contribute to the visibility of the phenomenon as well. … It’s become popularized in recent years.
A meteorological “bomb” almost sounds too crazy to be real. Are they as bad as the name makes them sound?
They most certainly are. The name isn’t an exaggeration — these storms develop explosively and quickly. They can produce destructive winds, coastal flooding and erosion, and, of course, very heavy precipitation. If the term conveys the importance and the danger associated with them, then I think that’s a good thing.
Are there indications climate change could affect the frequency of “bombs” in the future?
That’s a great question. We’re definitely expecting impacts for two reasons. First is the warming ocean. As the waters warm, they can add more moisture to the air, allowing the storms to dump more precipitation. Latent heating could also play a role intensifying the storms as well. These storms feed off the temperature gradient between the mild Gulf Stream and cold air over the land. Climate change could also periodically cause cold air to spill farther south, and when the two meet, there’s an increased risk for these extreme storms.
We also have to talk about rising sea levels. Because the waters are higher, a storm that 50 years ago wasn’t that bad could have a much bigger impact nowadays. And an extraordinary storm of the type we’re seeing today will have the potential to bring significant coastal flooding.