Millions in Northeast brace for winds, flooding from Tropical Storm Henri

Residents in southern New England and on Long Island braced for Tropical Storm Henri on Sunday, as heavy rain from the outer edges of the storm was already causing flash flooding in parts of the region.

The latest: Henri was downgraded to a tropical storm, but it was still expected to wreak havoc in parts of the Northeast, with storm surge and inland flooding among its greatest threats.

The big picture: Heavy rains interrupted the star-studded "We Love NYC: The Homecoming Concert" — an event attended by thousands of music fans in what organizers had hailed as "a celebration of New York City's comeback" from the pandemic, per CNN.

• The New York City Police Department tweeted almost three hours after the concert began that event-goers should head to the nearest exits in Central Park "due to approaching severe weather."
• Authorities issued a mandatory evacuation order for some residents near the water in Madison, Connecticut, while those on Fire Island were urged to evacuate on Saturday evening, per AP.

President Biden has approved Rhode Island, New York and Connecticut's emergency declarations.

• New York Gov. Andrew Cuomo called up 500 National Guard members to respond to likely flooding, along with 1,000 law enforcement officials who will be on duty in the affected areas.
• New York City Mayor Bill de Blasio declared a state of emergency for the city Saturday afternoon.
• In Connecticut, Gov. Ned Lamont (D) called up 200 National Guard members, according to the Hartford Courant.
• Sen. Richard Blumenthal said members of the Federal Emergency Management Agency were staging supplies across the region, such as food, medicine and generators from the military base in Westover, Massachusetts, per the Courant.
• On Rhode Island, Gov. Dan McKee signed an emergency declaration Friday ahead of Henri’s landfall, and said during a press briefing Saturday that five shelters across the state will open at approximately 8 p.m. He recommended that residents prepare for power outages and get supplies as soon as possible.

Of note: Biden spoke by phone on Saturday with Northeastern governors, FEMA administrator Deanne Criswell and Homeland Security adviser Liz Sherwood-Randall.

• On the call, Criswell "discussed the resources and supplies that FEMA is pre-positioning in the region, including over 700 response personnel, meals, tarps, and generators," the White House said.
• "They also discussed what the utility companies are doing to prepare for the potential for widespread power outages, including by moving additional line and tree crews and other equipment from outside the affected region where assistance can be surged from if needed," according to the readout of the call.

Go deeper: Tropical Storm Henri slams southern New England with high winds, flooding

Editor's note: This article has been updated with new details throughout, and to correct the spelling of Lamont's surname.