The National Weather Service has issued a hurricane warning from New Haven to Rhode Island, as Tropical Storm Henri heads for a direct hit on Connecticut, bringing the likelihood of severe flooding, high winds and widespread power outages across the state.

New tropical storm warnings also were issued early Saturday morning for the northern half of the state “until further notice,” according to the weather service, alongside new flood watches in effect across the state through Monday morning. A storm surge warning remains in effect from Greenwich to Cape Cod, with powerful ocean flooding potentially inundating shoreline communities.

“With the current forecasted track of Henri, we can expect heavy rainfall and high winds, with the potential for a significant amount of coastal flooding and urban flooding across Connecticut,” said Gov. Ned Lamont, who will return Saturday morning to the state from his vacation home in Maine. “I will be declaring a state of emergency in advance of the storm making landfall, which will enable the state to take any actions necessary to respond and protect the people of the state.”

At 8 a.m. Saturday, Henri was still about 500 miles from the New York City but marching north at 12 mph, according to the National Hurricane Center. The track will continue north-northeast throughout the day but is expected to take a turn to the north-northwest — more directly targeting Long Island and Connecticut — by tonight, forecasters said.

The state’s Emergency Operations Center was expected to be fully activated Saturday morning and the governor is calling 200 Guardsmen and women to state active duty to prepare teams and specialized equipment in support of the response, he said Friday evening.

“We’ll have the relevant state agencies there, as well as utility company representatives, to monitor and manage any issues that may arise,” Lamont said.

Lamont also said he is asking President Joe Biden for a pre-landfall emergency declaration to provide the state with federal assistance in anticipation of the impacts of the storm.

Eversource is warning of widespread power outages that could last up to 10 days.

“Henri has the potential for significant and lengthy outages. Customers should be prepared for multiday restoration, up to 5 to 10 days,” said Eversource spokesman Mitch Gross.

Eversource President and CEO Joe Nolan said the company predicts between 30% and 49% of its customers will lose power as a result of the storm. The company has brought in thousands of extra workers to respond to expected power outages.

Tropical Storm Henri, currently located in the Atlantic Ocean off the coast of the southeastern United States, is forecast to become a hurricane by Saturday and reach Connecticut by Sunday, causing significant rainfall and potential flooding.

If it makes landfall in Connecticut, it will be the first hurricane to do so since Hurricane Gloria in 1985.

“We only have so many threats of this magnitude that ever crop up during a year or even a decade,” said Bob Maxon, a meteorologist at NBC Connecticut. “People in their 20s and 30s have never experienced anything like the potential that’s there for Sunday and Monday.”

What can Connecticut expect this weekend?

Rain is expected to start early in the day Sunday, intensify Sunday afternoon and evening and then continue into Monday. Gary Lessor, chief meteorologist at the Western Connecticut State University Weather Center, said he expects Henri’s impact to be similar to that of Hurricane Irene, which did not make landfall in the state but still caused extensive flooding and damage.

The state could see as much as 8 inches of rainfall, he said. Central and western Connecticut will likely see the biggest impacts of rain, while the eastern part of the state will see the biggest impacts of wind.

The shoreline will see wind speeds of 45-65 mph generally, with a possibility of gusts as high as 70 mph. Lessor expects wind gusts in the inland part of the state to range as high as 45-60 mph. The wind will be strongest Sunday morning and early afternoon. Coastal flooding will also be a concern, he said.

“Obviously, stock up. Plan 5 days groceries, minimum,” he said. “Anything loose in the yard, secure it.”

The National Hurricane Center on Friday morning issued a storm surge watch for the entire Connecticut coastline, plus much of Long Island, Rhode Island and Cape Cod. Additionally, the center issued a tropical storm watch for all of Connecticut’s southern counties.

“A northward to north-northeastward motion is expected today, with a turn toward the north-northwest expected by tonight,” according to the hurricane center’s 5 a.m. forecast. “On the forecast track, Henri is expected to make landfall in Long Island or southern New England on Sunday ... Strengthening is forecast through tonight, and Henri is expected to become a hurricane later today and be at or near hurricane strength when it makes landfall in Long Island or southern New England.”

Joe Furey, co-chief meteorologist at WNTH News 8, said: “You plan for the worst, hope for the best, but the trend is not in our favor.”

“The more we look at it the worse it looks. Everyone’s got to get prepared,” he said. Everyone’s got to get the generators gassed up and do what you need to do, knowing you could be out of power for a week.”

Is the state ready?

Nolan said Friday that Eversource’s response would be “all hands on deck,” with more than 4,000 crews from across the country.

“You will see a massive presence of utility people in this state like you’ve never seen before,” Nolan said. “We’ll do everything we possibly can to get everyone back [in power] and get them back safely.”

Lamont’s office said state emergency management officials and municipal representatives spoke with the governor Friday afternoon to coordinate preparedness efforts at the state and local levels. Federal Emergency Management Agency officials have also pledged “assistance and resources to support Connecticut’s response and anticipated recovery from the storm,” said the office.

All state campgrounds will close on Saturday at 4 p.m. through at least Monday afternoon, the DEEP said, and state parks and forests may also close for day use this weekend.

Michael Passero, mayor of New London, said the city has been testing emergency equipment, prepping an emergency shelter and attempting to track homeless people to ensure their safety during the storm. Passero said all residents are encouraged to shelter in place Sunday.

“Keep your phones charged, stock up on bottled water, make sure that you’re putting away anything that could become a flying projectile in heavy winds,” he said. “Most importantly, during the storm stay off the roads and shelter in place.”

Chris Gasiorek, vice president of watercraft preservation and programs at the Mystic Seaport Museum, said he’s fielded more than 50 calls from panicked boaters seeking harbor before the storm. Located on the upper Mystic River, the museum’s docks often accommodate many community partners’ vessels during hurricanes and tropical storms. But much of that space is taken up by participants in a wooden boat show this weekend, so he’s working to find alternative solutions.

“All these [wooden] boats mostly travel from long distances and will not be able to leave tomorrow into threatening weather,” he said. “Tomorrow afternoon we’ll work with all of them and reposition boats so they’re in the safest positions, make sure the personnel are safe, or [see] if there’s a way we can get people off of boats into a safer location.”

What’s causing the extreme weather?

Connecticut has had an eventful summer of weather, with several heat waves, a wave of storms in mid-July and now a potential hurricane.

“June was third-hottest June in 116 years, July was the third-wettest July in 116 years, so you went from the heat to the wetness,” Furey said. “We just had flooding rains yesterday and now we’re going to bring Henri in.”

Maxon said the heavy rainfall in July, plus the storm Thursday, could exacerbate the threat posed by Tropical Storm Henri.

“You throw [the storm] in with the saturated soil because of the rainy July we had, the third-wettest July on record, we had substantial and significant flooding yesterday, and we’re going to try to throw four-to-six inches of rain into this situation?” Maxon said. “That can lead to a lot of freshwater flooding, power outages and tree damage.”

Experts say extreme weather events are likely to become more common in Connecticut due to the effects of climate change.