Blitzstorm: Extremely Rapid Ida Downpour Shocks NYC

Cars sit abandoned on the flooded Major Deegan Expressway following a night of extremely heavy rain from the remnants of Hurricane Ida in the Bronx borough of New York City on Sept. 2, 2021. (Spencer Platt/Getty Images)

News Analysis

Sept. 1 started as a regular rainy day in New York City. By 4 p.m., grey overcast sweated out just 0.13 inches of rain in Central Park, below normal for the time of the year, according to the National Weather Service (NWS). But by midnight, the city would suffer the deadliest weather disaster since Superstorm Sandy.

In some ways, this was a storm the city may have never seen before—unprecedented in the speed with which it drenched the city, leaving more than dozen dead in its wake.

Early Warnings

NWS New York saw a big storm coming, predicting the “remnants” of Hurricane Ida would bring nearly 4 inches of rain to the city and up to 8 inches in some areas upstate. Soil was already saturated with previous rainwaters, adding to the flood risk, it said.

“There may not be much rain going on at your location right now, but that will change as we head into the evening and overnight,” it warned in a 2:22 p.m. update on Sept. 1.

But was that really that serious? After all, the city weathered more than 7 inches of rain from Tropical Storm Henri with minimal damage just the week before. Could Ida, already downgraded to “tropical depression,” be any worse?

As the afternoon turned into evening, the rain intensified. The storm was to hit with full force between 6 and 8 p.m., according to the NWS.

Shortly before 7 p.m., the agency issued a Flash Flood Warning for the city and surrounding counties. The problem is, NWS used to issue thousands of those a year, prompting “a large number of complaints” about warnings “with perceived little impact,” the agency acknowledged (pdf). Even though the alerts are pushed to people’s phones through the emergency announcement system, many New Yorkers have become desensitized to them.

This time, it was for real.

Floodgates Open

In the next couple of hours, the city received a cold shower of stunning proportions, as if the heavy clouds opened their floodgates into a seemingly endless vertical stream.

Between roughly 8 p.m. and 9 p.m., over 3 inches of rain were recorded at the Central Park weather station, a record in its more than 150-year history.

But it was more than that. It decimated the previous record, set by Henri the week before, by some 65 percent.

Flash floods stormed through the metro area so suddenly and with such fervor some scenes resembled the aftermath of a burst dam more than precipitation.

Right before 9:30 p.m., the NWS issued a Flash Flood Emergency, a rare warning of an imminent life-threatening deluge. It was the first one ever in the state.

Within the next hour or so, images and videos started to appear on social media. Streets turning into rivers. A foaming torrent bursting into a midtown subway station, stopping a train in its tracks. Rainwater rushing like a waterfall down the stairs of a subway station uptown. Passengers balancing on seats in a shin-high flooded bus, the driver still plunging through the opaque waters to reach higher ground.

Flooding at 145th St subway station in Manhattan, New York City, on Sept. 1, 2021. (NTD)

Then the casualty reports came in.

Lives Lost

At around 10 p.m., police responded to a call about flooding at a Woodside, Queens, home on 64th Street. Upon arrival, officers found a woman, a man, and a 2-year-old boy unresponsive in their basement. They were pronounced dead on scene.

Shortly before 11 p.m., police found an unresponsive woman in a Forest Hills basement apartment in Queens. She was later pronounced dead.

A bit after 11 p.m., officers found a 43-year-old mother and her 22-year-old son unconscious in a basement on 183rd Street in Jamaica. The man was pronounced dead on scene, the woman later in a hospital.

Then before midnight, officers found an 86-year-old woman unresponsive in an apartment on 84th Street in Elmhurst, Queens. She was pronounced dead on scene by EMS.

At least 13 died in the city, NBC New York reported. All deaths appeared to have been caused by the flooding and involved basement apartments, police said.

The disaster halted subways and commuter trains and stripped 200,000 people of electricity in the tri-state area.

Local officials blamed climate change and stressed the need for federal financing for resiliency projects.

“We have to figure out what we’re not doing right,” said Council Member I. Daneek Miller, representative for a southeast Queens district that includes several flooding hot spots, at a Sept. 2 press conference.

Flanked by Gov. Kathy Hochul, Mayor Bill de Blasio, and Sen. Chuck Schumer (D-N.Y.), he pointed out his district received substantial federal funding for resiliency projects after Sandy, but the measures weren’t enough.

“Two weeks ago, when we had the major flood, then the record-breaker, we were ok,” he said. “This was different and the loss of lives are unacceptable.”