Henri to leave Northeast Monday night, flood watches remain in effect

Rail service in parts of New York and Connecticut will be halted Sunday due to Henri.

The Long Island Rail Road will be suspending service east of Patchogue on the Montauk Branch and on the Greenport line. 

Metro-North, which serves New York and Connecticut, will be suspending service on the Wassaic Branch of the Harlem Line and on the entire New Haven Line, including the New Canaan, Danbury and Waterbury branches. 

In Connecticut, service on the rail lines Shore Line East and Hartford Line is suspended starting Sunday "until further notice."

Amtrak also announced it would be canceling all Northeast Corridor service, including Northeast Regional and Acela, between New York and Boston on Sunday.

Flight cancellations are also expected in the region.

"Port Authority expects flights to be canceled," Gov. Andrew Cuomo said during a briefing Saturday. "Obviously I would check with your airline before you go to the airport tomorrow into Monday, maybe Tuesday."

New York City Mayor Bill de Blasio defended continuing on with its "We Love NYC Homecoming Concert" Saturday evening, as the city prepares for Hurricane Henri.

"Since the real impact is not expected until well after the concert, we believe absolutely we can do both these things at once," de Blasio said during a press briefing Saturday, as the concert was set to kick off in Central Park with performers including Bruce Springsteen and Patti Smith.

The mayor urged concertgoers to go straight home at the end of the night. "If you're going to the concert ... go home right after and get ready for tomorrow," he said.

De Blasio, who declared a state of emergency for NYC earlier on Saturday, said the city is preparing for heavy rain, wind and downed trees.

-ABC News' Matt Foster

President Joe Biden held a call with the governors of six northeastern states Saturday to discuss Hurricane Henri, the White House said. 

The governors are working with Federal Emergency Management Agency and the National Guard to prepare for possible "widespread power outages, coastal storm surge, and inland flooding," the White House said in a statement.

FEMA has pre-positioned over 700 response personnel, meals, tarps and generators in the region.

"On the call, the President made clear that states have the full support of the Federal government to aid local emergency response efforts," the White House said.

Those on the call included New York Gov. Andrew Cuomo, who is in his final days of office after resigning earlier this month following sexual harassment allegations. His successor, Lt. Gov. Kathy Hochul, also joined the call, along with the governors of Connecticut, Massachusetts, Maine, New Jersey and Rhode Island.

Flash flood watches are in effect for seven states, from Delaware to Vermont, as Hurricane Henri is expected to bring heavy rain to the Northeast.

The flash flooding threat is particularly high across Connecticut, Long Island, New York City, the Hudson Valley and parts of New Jersey. Some areas could see up to 10 inches of rain.  

Storm surge also continues to be a major threat, especially for parts of Long Island and coastal Connecticut, Rhode Island and Massachusetts, where 3 to 5 feet of surge is possible. 

Hurricane warnings remain in effect for Suffolk County, coastal Connecticut and coastal Rhode Island. Wind gusts as high as 74 mph could cause widespread damage in these areas.