The New York branch of the NWS issued a 'Flash Flood Emergency' for the New York metropolitan area on Wednesday, alerting residents that remnants of heavy rains and high winds from Hurricane Ida could be still be deadly.
According to NWS-New York, New York City observed rainfall rates between at least three and five inches an hour.
The alert is set to remain in place until 11:30 p.m. local time.
New York City Mayor Bill de Blasio declared a state of emergency for his jurisdiction late last night, noting the metropolitan area is "enduring an historic weather event tonight with record breaking rain across the city, brutal flooding and dangerous conditions on our roads."
The New York City Subway completely suspended operations before 11 p.m. local time and evacuated numerous stations amid the continued flooding.
Social media footage recorded in Brooklyn's Park Slope neighborhood showed that street floodwaters that partially submerged parked vehicles. Another clip showed a minivan attempting to traverse the high water, despite the NWS' warnings.
NYC residents in lower-level housing units were advised by New York state government to "keep materials such as sandbags, plywood, plastic sheeting, and lumber on hand to help protect your home."
A slew of social media footage from various neighborhoods showed floodwaters violently invading locals' homes.
NWS-New York's first-ever 'Flash Flood Emergency' was issued to northeast New Jersey earlier Wednesday evening.
New Jersey Governor Phil Murphy went on to declare a state of emergency for the Garden State.
"We will use every resource at our disposal to ensure the safety of New Jerseyans," he tweeted around 10 p.m. local time. "Stay off the roads, stay home, and stay safe."
The Newark Liberty International Airport reported 3.4 inches of rain between the hours of 8 and 9 p.m. local time.
Areas of northern New Jersey are said to be at the highest risk for flash flooding, as officials expect to see more than six inches of rainfall within a short timespan.