Heat Dome Blankets New York, but it’s different from those plaguing the West
Damn, it’s hot outside. Thermometers at LaGuardia Airport reported a second consecutive day of temperatures in the 90s, with another scheduled for Friday. For New Yorkers wondering why, there are only five words: thermal dome and climate change.
A heat dome has migrated west from the Atlantic Ocean over the past two days, trapping the scorching air over the northeast coast and pushing any respite cooler than the region could typically receive from ocean breezes. People are probably familiar with the meteorological term, given that a similar event propelled massive wildfires across the west earlier this summer.
“Those in the northwest at the end of June were much worse, much worse than what we see in the northeast today and tomorrow,” said Sean Sublette, a meteorologist with Central Climate, a science and media organization based in Princeton, New Jersey.
Despite the widespread fervor for heated domes in recent months, these phenomena are actually a regular occurrence during the summer. As the capital weather gang Explain, very hot days can cook the air near the Earth’s surface. This hot gas pocket tries to expand vertically, but is then pushed downward by the higher pressure from the upper atmosphere.
“It’s a big cane, a mountain of air,” Sublette said. “It turns clockwise, very slowly through the depth of the atmosphere … I mean, 18,000 to 20,000 feet or so.”
As this extra pressure squats in the northeast area, it heats the air more and diverts other cooler weather systems away from us. (Fun fact: In 1960, Engineer Buckminster Fuller proposed a “two mile geodesic dome covering Midtown Manhattan that would regulate weather conditions and reduce air pollution.” We need you here and now, Bucky! )
Climate change comes into play because, in general, it increases the frequency of extreme heat in the tri-state region. Our days are warmer more often. When a heat dome takes over the city, it overlaps our human-caused climate change, only making what would normally be bad worse.
Sublette and her colleagues at Climate Central are monitoring the contribution to global warming in real time. Heat and humidity extremes like Thursday’s are much more likely now compared to the 1970s.
“The same type of heated dome that could have produced 90 or 92 degrees [Fahrenheit], 40 or 50 years ago will start producing 96, 97 degrees, today, ”Sublette said.
It’s so hot that Mayor Bill de Blasio is advising all New Yorkers to stay indoors and near the air conditioning on Thursday. He also asked residents to take care of each other.
“Keep an eye on your children if they are playing outside. Don’t leave them outside for too long, of course. Check the neighbors, loved ones, our elderly, ”de Blasio said in a briefing Thursday. The city issued an extended heat warning until 8 p.m. tonight. The swimming pools will also remain open until then. (Here is a map of city cooling centers in case you need it on Friday).
The five boroughs are on their way to an average or slightly above average summer in terms of heatwaves. In an average year, there are about 17 days above 90 degrees Fahrenheit, Sublette said. Assuming the region exceeds 90 days on Friday, that would bring this year’s total to 14. He adds that the last time there were more than 30 days in Central Park at or above 90, it was was in 2010.
But luckily the main difference between our thermal dome on the east coast and the ones that hit the west in June and this week is the length. Western heat waves last for up to a week or more, while the New York Dome is expected to dissipate by this weekend.
Katherine Fung and Jen Carlson contributed reporting.