Thousands of flights canceled at Newark, LaGuardia and Kennedy airports. Schools closed by Mayor Bill de Blasio nearly 24 hours before the first flakes were predicted to fall. Libraries shuttered, above-ground subway stations closed. Snow plows back in action, shaking off dreams of spring hibernation. New York City prepared for another late snowstorm.
For officials concerned about keeping people safe and not wanting precipitation to turn into political disaster, any big storm is a major event. This one could be a record for late-season storms — but if so, it’s more than a headache for politicians and parents.
It can also be a “teachable moment,” says Sean Sublette, meteorologist at Climate Central, a research and news organization devoted to climate change. The lesson that it teaches? “One of the things we need to remember is we are going to have more extreme weather.”
Why are we seeing more intense storms?
In certain circumstances, Sublette says, generally higher temperatures could paradoxically lead to bigger snowstorms.
For every degree Fahrenheit of temperature increase, about four percent more water can be stored in the atmosphere during saturated storm conditions. When temperatures stay below freezing, that extra water can turn into more snow.
Sublette and Climate Central are careful to note that a particular event doesn’t prove or disprove the existence of climate change, just as a cold snap in spring doesn’t mean worldwide temperatures aren’t rising. That’s weather, not climate.
But the scientific consensus is that changing weather patterns can cause more intense weather events. The 2015 New York City Panel on Climate Change report warns that increased “intense precipitation” is likely for hurricanes in the area.
The report did not describe a definite change in future nor’easters, but projected 4 percent to 11 percent increases in mean annual precipitation by the 2050s compared to the 1980s; along with more frequent heat waves and double digit inches of sea level rise.
Conditions like that can make a big storm more serious. With water levels up compared to a century ago, says Sublette, Superstorm Sandy had a larger effect — the difference between water just making it into your basement and reaching the electrical sockets or higher.
Is climate change responsible?
Climate Central has an “attribution” team that looks back at high profile weather events to determine the extent to which they can be attributed to climate change. The team released a report on the run of warm weather last month — the second-warmest mainland February on record nationally.
Will they do a similar report for Tuesday’s storm? Sublette said the team doesn’t decide whether or not to run such an analysis until after the event happens. Speaking Monday afternoon, he said there was still plenty of room for the storm to turn into sleet and be a general bust, foiling the best-laid plans of politicians and citizens stocking up at local bodegas and supermarkets.
While the storm itself will only tell us so much, Sublette cites analysis from the Washington Post’s Capital Weather Gang team noting that seven of NYC’s nine biggest snowstorms have come since 1996.
Climate change locally wouldn’t mean that you’ll see bad storms every day. Instead, the deluge so unlikely it’s called a 100-year flood will be far more common, says Sublette. It’s hard to remind people of that future when the weather’s nice, but maybe it hits home in darker weather.
“This is when people are paying attention.”