Members of the Lodi, NJ fire department conduct a water rescue of trapped residents Thursday after torrential rainfall from the remains of Hurricane Ida. Michael Candelori / NurPhoto / Reuters hide caption
Michael Candelori / NurPhoto / Reuters
Michael Candelori / NurPhoto / Reuters
How did the remnants of Hurricane Ida wreak deadly havoc in Pennsylvania, New Jersey, and New York days after the system hit the Gulf Coast – about 1,000 miles away?
One reason is that “just the right mix of weather conditions” was in place to fuel the system, according to Tripti Bhattacharya, assistant professor of earth and environmental sciences at Syracuse University.
“A storm like this would have been exceptionally rare 20 or 50 years ago,” she told NPR. “But we have to start thinking that if the climate warms up, it will become the norm.”
Bhattacharya’s research on regional rainfall and climate change was cited in the recent United Nations climate change report.
NOTE: This interview has been edited and condensed for the sake of clarity.
Where were you surprised to see what Ida was doing in the northeast after devastating parts of the Gulf Coast?
Yes i was surprised. You know, the remnants of hurricanes make up a lot of the extreme rainfall in the northeast, so I was expecting extreme rainfall.
It turned out that it was just the right mix of weather conditions when the remains of Ida encountered another system, an extra-tropical front. They combined to create really extreme rainfall over New York and the surrounding area.
Ida also spent time over a particularly warm patch of water in the northern Gulf of Mexico that made it intensify very quickly.
After decades of research, we expect hurricanes to become more intense as a result of global warming. That way, Ida doesn’t surprise.
Could you have imagined such a storm 20 years ago?
A storm like this would have been exceptionally rare 20 or 50 years ago. But we have to start thinking that as the climate warms up, it will become the norm.
The physics is very simple: when the atmosphere warms up, it can hold more moisture – and that means more fuel for rain.
We have all seen hurricane maps showing areas at risk. It seems more difficult to get people to prepare for a major rain event.
We’re moving into a world we’ve never seen before. When people say “New York City floods” what is our reference for that? I don’t think anyone can imagine subways flooding so dramatically. I think it’s about getting people to take warnings more seriously because now we’ve seen what can happen.
It also speaks to the importance of a really good infrastructure for weather forecasting. The predictions for this storm were remarkably good.
Floods hit the east of the US, while parts of the west are suffering from extreme drought. Are these situations related?
As the atmosphere becomes more humid due to climate change, we basically get a reinforcement of the historical patterns of wet and dry.
In a global sense, more moisture is moving to places like the Gulf Coast and the East Coast. And more moisture is extracted from historically dry places like the west.
Rescue workers and supplies were set up on the Gulf Coast in advance of the storm. Should more states make such preparations?
Yes sir. We’ll only see more of it, especially if we don’t act to curb our emissions. As a country, it is very important to have a real conversation about adaptation, both in terms of infrastructure and contingency plans.
There are big differences between the way cities and houses are built in the northeast and the Gulf Coast. What about that dynamic?
There is definitely a geography to be risked. If you’ve been to New York’s uptown, you haven’t seen as much flooding as you did in Lower Manhattan or other parts of the city.
To be careful about who will be most affected, you need to look at the vulnerability maps and how that affects income – which affects your ability to leave in the blink of an eye.