Philippe Storm Path Raises Concern for ‘Dangerous’ Flash Flooding

Post-tropical cyclone Philippe is barreling toward the Northeast, posing a “dangerous” risk of flash flooding for the already sodden states in the region.

As of Friday morning, Philippe had been downgraded to a post-tropical cyclone by the National Hurricane Center (NHC). Philippe’s maximum sustained winds were near 50 miles per hour, with the NHC warning that the storm could strengthen over the next day. The advisory forecasts rainfall, flash flooding and winds to impact much of the Northeast by the end of the weekend.

Last week, heavy rainfall plagued New York City, leading to severe flooding that submerged streets. The National Weather Service (NWS) urged area residents to seek higher ground during the storm as flooding inundated the city. Other Northeastern cities also received more rainfall than normal during September. The increased rainfall even worsened a sinkhole near an interstate in New Jersey.

AccuWeather meteorologists are now forecasting that the incoming storm could dump 2 to 4 inches of rain along a narrow corridor from Long Island to New England. Widespread amounts of 1 to 2 inches also are forecast to fall later this weekend and into next week. The forecast warned area residents that “dangerous” flash flooding could occur. The flash flooding risk is exacerbated for areas like New York City because of last week’s rain, and because the ground is already saturated, flooding is more likely.

AccuWeather meteorologist Alex DaSilva told Newsweek on Friday that New York City is forecast to receive 1 to 2 inches of rain, but that if a slow-moving thunderstorm passes over it, there could be more rain dumped on the region. He also stressed that even though Philippe is no longer a tropical storm, it is still dangerous.

“Regardless of its classification, Philippe is still a very powerful storm,” he said.

The worst of the rain is forecast in Canada, with 4 to 8 inches predicted for north of Montreal. However, the risk for flash flooding in New York City is still high.

“While we expect the best chance for flooding this time will be north and east of New York City, should extreme rainfall rates above 1 inch per hour occur in urban areas, such as New York City area, flash flooding with rapidly rising water can quickly escalate into a life-threatening situation in a matter of minutes, as urban environments have many impervious surfaces such as sidewalks and streets which promotes greater runoff,” AccuWeather chief meteorologist Jonathan Porter said in a report.

On Friday, New York City Mayor Eric Adams warned residents of the incoming flood risk.

“New Yorkers: periods of heavy rain and potential flooding are forecast late tonight into tomorrow,” he posted on X, formerly Twitter. “We’ve activated the City’s Flash Flood Emergency Plan, proactively staging resources and teams.”

Meanwhile, Philippe could also grow stronger as it is expected to merge with another storm brewing off the East Coast. If the storms merge, northern and eastern New England would feel the brunt of the impact later this weekend. DaSilva told Newsweek that the storms will make landfall in Maine on Sunday. The merging storms also would exacerbate flash flooding and could cause it to become “widespread, dangerous and highly disruptive.”