New York sets record thanks to tropical storm Henri

Did you hear that it rained a lot the other day?

Well he did. Let’s start with the book of records. The rainiest hour on record in New York (1.94 inches from 10 p.m. to 11 p.m. on Saturday) produced the the rainiest August 21 record (4.45 inches), which was immediately followed by the wettest August 22 on record (2.67 inches).

This deluge, courtesy of Tropical Storm Henri, in turn produced what is already the fifth wettest August on record, on the heels of the wettest third of July on file to make it second wettest summer never recorded in the city – 23.36 inches so far, Monday afternoon.

It’s almost two feet of rain.

In 36 hours, from Saturday night to Monday morning alone, 8.05 inches of rain fell in Central Park.

It’s almost two months of rain in a day and a half.

If there had been snow, it would have been nearly nine feet.

We asked a meteorologist from the National Weather Service in Upton, NY, to characterize this weather event.

“It’s a great amount of water falling from the sky in such a short time,” said meteorologist Dominic Ramunni.

Think about it.

“It really is,” he added.

Maybe eight inches doesn’t sound like much.

But it’s actually a lot. An inch of rain falling on an acre of land weighs about 113 tons. Eight inches of rain in New York City’s 302.6 square miles weighs about 175 million tons and includes more than 42 billion gallons of water.

This is where you run into problems. The city’s old combined storm sewer system was not built to handle this.

What it was designed for is only 3.8 billion gallons per day. Beyond that, runoff and mixed wastewater flow into the harbor. Either that or he is backing down into the street, although Vincent Sapienza, the city’s environmental commissioner, said on Monday that this was happening much less than before – and that the flooding in the streets that has arisen around the city this weekend could have been a lot worse, considering the amount of rain that fell.

The city is building a parallel pipeline system that will treat only stormwater, but it still has thousands of miles of pipeline to go. “It will take decades,” Sapienza said.

Videos taken in the underground subway system show that the rain falls as freely as if the inside were outside, although Aaron Donovan, spokesman for the Metropolitan Transportation Authority, said that despite “dozens of thousands of openings where water can enter the metro system ”, there were only a few localized service interruptions.

Heavy amounts of rain were recorded across the region. According to amateur weather observers cited by the meteorological service, 9.22 inches fell in Oakland, NJ, in Bergen County, 9.85 inches were recorded along the East River in Brooklyn Heights, and nearly eight inches fell in Prospect Park in Brooklyn. In nearby Mount Prospect Park, a stone staircase has been magically transformed into a waterfall.

Here’s another way to think about rain: In Central Park, official precipitation is measured using a device called a tilting rain gauge. Whenever a measurable amount of rain – one hundredth of an inch – falls into the dipstick cup, the cup pours water, advances a counter, and resets itself. (“I bought one from my parents for Christmas a few years ago,” said Mr. Ramunni of the weather service. “Actually, it was more of a present for me.”)

During that hour on Saturday night when nearly two inches fell, the gauge flipped every 19 seconds.

The whole year was not like that. Precipitation in the first half of 2021, in fact, was 13% below normal.

But since July 1, half of the days have had measurable rainfall in New York City. Every other day – drip, drip, pour.

The scary thing, of course, is that large amounts of rain can become less and less rare.

“I don’t want to dwell too much on this,” Mr. Ramunni said, “but with a warmer climate, you’re going to see more water vapor in the air, and more water vapor. in the air leads to more rain. “

What is all this rain for, then? Mushrooms, do you think. And July has been an amazing month for them. “You can’t take a step anywhere without stepping on a mushroom,” said Paul Sadowski, secretary of the New York Mycological Society.

But even mushrooms have their limits. A mushroom is what is called the fruiting body of a predominantly underground life form. After the July explosion, the August rains exhausted the town’s mushrooms.

“The whole fungal organism – its purpose in existence is to reproduce,” Mr. Sadowski said. “Once he’s produced his fruiting body, it’s done.”