NEW YORK CITY — "New Yorkers in those neighborhoods living in basements and below grade are urged to move to higher ground tonight," the agency stated. Mayor Zohran Mamdani added specific guidance for those in lower-level housing. "If you live in a basement apartment, know your exits before you go to bed and be ready to move to a higher floor if conditions worsen," he said.

Mamdani also addressed drivers and community preparedness. "If you're driving Sunday morning, give yourself extra time and never drive through a flooded street," he said. He urged residents to look out for one another.

"Check on neighbors who may need extra help, and make sure you can receive emergency alerts by texting NOTIFYNYC to 692-692," he said. "A few simple steps tonight can help keep you and your neighbors safe tomorrow."

National Weather Service meteorologist James Tomasini provided details on the expected rainfall amounts. Tomasini said rainfall totals between 1-2 inches are expected, with up to 3 inches in some areas. "All this activity is kind of right out ahead of it. That will shift kind of through the area and east of the area," he said.

He noted that the system would move through relatively quickly. "Expecting the heaviest rain to really be done sometime around noon, and then a gradual clearing into the afternoon," he said.

The National Weather Service expects 1.5 to 3 inches of rain across New York City, with the highest amounts possible in eastern Brooklyn and Queens. Forecasters said the greatest threat for heavy rain and flash flooding in New York City is between 5 a.m. and 10 a.m. Sunday. Officials said rainfall rates could reach 1 to 2 inches per hour, with the strongest storms capable of producing up to 2.5 inches per hour.

NYC Emergency Management Commissioner Christina Farrell warned that intense rainfall could quickly overwhelm drainage systems. "Heavy rain can overwhelm streets and drainage systems in minutes, and the most intense rain is expected when many New Yorkers will be asleep," she said. She noted the potential intensity of the morning storms.

"The strongest storms Sunday morning could drop 2 to 2.5 inches of rain in a single hour," she said. "Do not wait until you see water rising to make a plan."

Mamdani outlined the operational response underway across the city. "Our crews are clearing catch basins, agencies are preparing and emergency teams will be working through the night while most of the city sleeps," he said. Service animals and pets are permitted at New York City weather shelters.

The National Weather Service issued flood watches late Saturday through early Sunday for parts of Maryland, Pennsylvania, Delaware, and New Jersey. The agency also issued a Flood Watch for Northern New Haven from 12:02PM EDT until 2:00PM EDT on September 13. NYC Emergency Management stated that 5 to 7 inches of rain could fall in Nassau and Suffolk counties, as well as in southern Connecticut. The National Weather Service stated that 1 to 2 inches of rain could fall within an hour in southern Fairfield County.

"A small shift in where the rain sets up would bring 5 to 7 inch totals and a much higher flash flooding risk into eastern Brooklyn and Queens," NYC Emergency Management said. The National Weather Service noted the atmospheric conditions driving the event. "The combination of instability, deep moisture, and forcing, may lead to an elevated threat for excessive rainfall and severe thunderstorms," the agency said.

It warned of specific vulnerabilities in the urban landscape. "Flash flooding of small creeks and streams, urban areas, highways, streets and underpasses, as well as other poor drainage and low-lying areas," the agency said. The agency also issued a standard safety warning for motorists. "Turn around, don't drown when encountering flooded roads. Most flood deaths occur in vehicles," it said. It cautioned that localized outcomes remain difficult to predict with precision. "While it remains uncertain whether these narrow bands of heavier rain will occur, localized flash flooding is possible, especially if it occurs over a vulnerable urban center," the agency said.

Timeline

NYC Emergency Management activated its Flash Flood Emergency Plan on Thursday, September 11, 2026. The National Weather Service issued a Flood Watch for New York City from 4 a.m. to noon on Sunday, September 13, 2026, and the city activated the Flash Flood Emergency Plan on Thursday, September 10, 2026, with city agencies preparing for potential flooding impacts before conditions improve Sunday afternoon.

What's New

James Tomasini, a meteorologist in the National Weather Service’s New York office, said rainfall totals between 1-2 inches are expected, with up to 3 inches in some areas. "The strongest storms Sunday morning could drop 2 to 2.5 inches of rain in a single hour." "Check on neighbors who may need extra help, and make sure you can receive emergency alerts by texting NOTIFYNYC to 692-692." "If you're driving Sunday morning, give yourself extra time and never drive through a flooded street."

How Sources Differ

Regarding rainfall figures for the national weather service, James Tomasini, a meteorologist in the National Weather Service’s New York office, said rainfall totals between 1-2 inches are expected, with up to 3 inches in some areas, while the National Weather Service rainfall forecast expects 1.5 to 3 inches of rain across New York City, with the highest amounts possible in eastern Brooklyn and Queens. Regarding rainfall figures for the national weather service, James Tomasini, a meteorologist in the National Weather Service’s New York office, said rainfall totals between 1-2 inches are expected, with up to 3 inches in some areas, while the National Weather Service warning text stated that 1 to 2 inches of rain could fall within an hour in southern Fairfield County. Regarding inches, Christina Farrell said the strongest storms Sunday morning could drop 2 to 2.5 inches of rain in a single hour, while the National Weather Service warning text stated that 1 to 2 inches of rain could fall within an hour in southern Fairfield County. Regarding york city, New York City Emergency Management stated that 5 to 7 inches of rain could fall in Nassau and Suffolk counties, as well as in southern Connecticut, while the National Weather Service rainfall forecast expects 1.5 to 3 inches of rain across New York City, with the highest amounts possible in eastern Brooklyn and Queens. Regarding eastern brooklyn, New York City Emergency Management said a small shift in where the rain sets up would bring 5 to 7 inch totals and a much higher flash flooding risk into eastern Brooklyn and Queens, while the National Weather Service rainfall forecast expects 1.5 to 3 inches of rain across New York City, with the highest amounts possible in eastern Brooklyn and Queens.

Why It Matters

New York City opened 51 weather shelters for residents vulnerable to floodwaters, including people in basement apartments, representing a significant mobilization of resources compared to standard operations. The activation of the Flash Flood Emergency Plan on Thursday, September 10, 2026, indicates that city agencies began preparations days in advance of the Sunday morning flood watch. The National Weather Service expects 1.5 to 3 inches of rain across New York City, with the highest amounts possible in eastern Brooklyn and Queens, posing a direct threat to infrastructure and residents in low-lying areas.

The potential for rainfall rates to reach 1 to 2 inches per hour, with the strongest storms capable of producing up to 2.5 inches per hour, shows the strain on urban drainage systems. NYC Emergency Management Commissioner Christina Farrell warned that intense rainfall could quickly overwhelm drainage systems, noting that heavy rain can overwhelm streets and drainage systems in minutes. The uncertainty regarding whether narrow bands of heavier rain will occur over vulnerable urban centers means that localized flash flooding remains a primary concern for emergency responders and residents alike.