New Jersey Gov. Phil Murphy declared a state of emergency Thursday as Hurricane Erin brings high surf and dangerous rip currents to beaches along the East Coast. 

Officials said parts of New Jersey will experience sustained winds of up to 50 mph, waves on the Jersey Shore may be as high as 17 feet, and flood-prone areas may see up to 3 feet of water. 

"Over the past couple of days, we have seen the effects of Hurricane Erin along the Jersey Shore in the form of dangerous rip tides. Today and tomorrow will be no exception," Murphy said. "As the storm moves past New Jersey over the next 24 hours, we are expecting high surf and rip currents, coastal and flash flooding, and a high erosion risk in parts of the state. We ask all New Jerseyans to monitor local weather forecasts and warnings and stay informed on evacuation protocols, especially if you're down the Shore."    

The state of emergency took effect at 2 p.m. Thursday. A coastal flood warning is also in effect for the Jersey Shore and high surf advisory for New York's south-facing beaches. 

Many beaches remain closed to swimming, and officials urge people to avoid the water.

Coastal flood warning for Jersey Shore

While Hurricane Erin is forecast to stay hundreds of miles offshore, the East Coast is still feeling its indirect impacts.

Towns along the Jersey Shore have been preparing for the storm, telling people to move their cars to higher ground before the water levels rise. Residents have also been asked to secure their outdoor furniture and check on their boats, docks and slips to make sure they are tied up tight. 

In Sea Bright, which sits between the Atlantic Ocean and two rivers, residents say they're hopeful rock barriers along the ocean and metal bulkheads placed along the Shrewsbury River after Superstorm Sandy will help keep them safe.

At Manasquan Inlet Beach, massive waves crashed against the rocks. The winds from Hurricane Erin were also kicking up the sand, and beachgoers could feel it hitting them in the face. 

At the Riverside Cafe in the inlet, owner Michael Parziale moved his vehicles to higher ground as a precaution. The cafe went through Superstorm Sandy. 

"We witnessed so many nor'easters and hurricanes. We always watch the tidal phases for the moon, and it's going to be a new moon, so we know it's going to get increased," Parziale said. 

Some beaches along the Shore saw winds up to 45 miles per hour, toppling over lifeguard posts in Seaside Park. Thunderous waves crashed along a barrier in Wildwood, causing the street to flood. 

High surf drawing people to beach for a look, if not a swim

A lot of people came to the beach to watch the power of mother nature in the churning ocean. 

"The wind is very strong. We're, like, both falling over, and the sand is, like, hitting us," Savannah Gill said. "It's kind of crazy. It's very choppy. Very thick looking and spooky." 

"It's been rough for the past couple weeks, but now it's just twice as bad," Marcia Dorinas said. 

Earlier this week, Murphy told beachgoers, "don't go in the water." Thursday, Erin threw a wrench in the plans of some folks on vacation down the Shore. 

"We were here for a lot of fishing and a lot of outdoor activities, but we are making the best of it. We are going to go play some mini golf right now," Connecticut resident Dan Ruane said. 

"We usually like the big waves in Vermont, seeing the big ripples in the ponds. It's exciting to see some big waves, but unfortunately we can't go in them," Vermont resident Jackson Ruane said. 

The same was true for onlookers in Southampton on Long Island. 

"It's indescribable, really," Darrell Harris said. 

"We don't want our beaches to be taken from us, but this is a very beautiful sight to see," Maria Harris said. 

Rip currents and red flags along Long Island

Erin has also prompted New York officials to shut down beaches in New York City and some on Long Island. New York City beaches will remain closed to swimming Friday.

Long Island officials discussed their emergency preparedness for the hurricane season in a rare joint appearance. The two gave a unified message about the importance of hurricane preparedness as they ready for beach erosion and possible flooding. In Nassau County, nuisance flooding may take place in areas like Long Beach and Freeport. In Suffolk, Fire Island and Mantauk are being closely watched. 

Nassau County Executive Bruce Blakeman and Suffolk County Executive Ed Romaine said, with Erin being the first hurricane of the season, it's important that all Long Islanders have a plan. 

"Just in case, if you live along the shore or in a low-lying area, please make sure that you have water. Have a plan to leave, God forbid we should have to make that determination. Have a place to go. Keep non-perishable food and manual can openers available. In case there's a power outage, make sure you have flashlights and batteries. Do not, do not use candles," Blakeman said. 

"We're prepared for this hurricane as best we can. It's not going to do a lot of damage, but it will create erosion. It will create flooding," Romaine said. 

They emphasized pet preparedness too. 

The island was expecting even bigger waves -- up to 16 feet in some areas -- and water levels could be 2 to 2.5 feet above normal. 

Towns like Southampton and Quogue declared states of emergency. Crews have been using truckloads of sand to reinforce dunes, fearing the heavy surf will erode beaches and damage shoreline properties. 

Dune erosion is already impacting the East End. 

"We are concerned about erosion, and that is our main concern with high tides tonight and tomorrow morning," New York State Parks regional director George Gorman said. 

"The declaration of a state of emergency allows the town to be able to take special actions if needed to protect public safety," Ryan Murphy of Southampton Town Emergency Management said. 

"We have to secure the vessels, keep them safe at the dock, extra lines, monitoring," said commercial fishing boat Capt. John Berglin. 

Wind gusts up to 30-40 mph along the coast could also bring down trees or power lines, especially with the ground saturated from recent rain. 

Neither county is declaring a state of emergency or any kind of evacuations, but it's Mother Nature, so things could change. Village and town beaches will assess when reopening is safe. 

"Concerned about the riptides and safety of the people swimming in the ocean," Quogue Village beach lifeguard manager Ryan Fay said. 

The restaurants along main streets in towns across Long Island are teeming with tourists, but restaurants along beach roads are closed. 

Click here for the latest forecast, live radar and weather alerts from our First Alert Weather team.