Hurricane Erin to lash Long Island's South Shore, bringing coastal flooding, erosion Thursday as it skirts East Coast waters

Hurricane Erin will force swimmers off Long Island's ocean beaches, send waves crashing into vulnerable shorelines and generate coastal flooding intensified at high tide and under a moonlit sky as the storm passes southeast of the region Thursday into Friday.

"An approaching new moon will lead to astronomical tide levels on top of increased surf and surge conditions Thursday into Friday," the National Weather Service said in an advisory Thursday.

"Starting with the Thursday evening high tide cycle, we're going to start to see an increase in coastal flood impacts, especially for the South Shore bay locations of Long Island," meteorologist Jay Engle with the weather service's Upton office said. The North Shore could also experience flooding Thursday evening, he added.

Friday morning, the East End and the North Fork have a greater chance for flooding, but Friday evening, Engle said, flooding will be a concern for "mainly the western South Shore bays."

The weather service has issued advisories for high surf and rip currents and a coastal flood warning will take effect from 5 p.m. Thursday to 1 a.m. Friday for Long Island's South Shore. Coastal flood advisories are similarly in effect from 5 a.m. to 1 p.m. Friday and 6 p.m. Friday to 2 p.m. Saturday. 

The agency also issued a coastal flood warning for northeastern Suffolk County from 5 p.m. Thursday through 3 a.m. Friday and a coastal flood advisory from 5 a.m. to 2 p.m. Friday.

Parts of southern Nassau and southwestern Suffolk could face up to 2½ feet of coastal inundation, while the eastern portion of Suffolk could face 2 feet of inundation in localized areas along both shores, according to the hurricane center.

The weather service said "widespread areas of dune erosion," including local overwashes or flooding over the dunes, are likely during the Thursday evening and Friday morning high tides, due to the 10 to 15-foot waves expected and the elevated storm tide.

The storm was tracking north around 520 miles west of Bermuda and 295 miles southeast of Cape Hatteras, North Carolina, the hurricane center said Wednesday evening. Now a Category 2, Erin was expected to turn northeast overnight into Thursday and pass Long Island hundreds of miles offshore Thursday into Friday.

Strong winds are expected to gust to 25 to 35 mph Thursday morning into midday Friday in coastal locations, with isolated gusts up to 40 mph possible. The highest winds are expected across eastern Long Island, forecasters said.

After Gov. Kathy Hochul ordered all state ocean beaches on Long Island closed through Thursday, the Suffolk Health Department Wednesday closed all Atlantic Ocean beaches through Saturday, saying they "shall remain closed until Saturday morning ... due to hazardous conditions expected as a result of Hurricane Erin."

South Shore beaches remained open to visitors, including the state parks, but with no swimming allowed, authorities said. Typically, lifeguards are posted at the water's edge in these conditions, to prevent beachgoers from entering the surf.

Southampton Town Supervisor Maria Z. Moore declared a state of emergency beginning at 3 p.m. Wednesday due to the "indirect effects of Hurricane Erin passing offshore of Long Island," likely one of several Long Island towns to do so as the storms gets closer.

Nassau and Suffolk county officials announced a joint news conference Thursday morning on emergency preparedness.

Rain in the region from a different weather system will become "less widespread" after 4 a.m. Thursday, Engle said. A slight chance of showers will linger Thursday morning, but the island is expected to be dry by Thursday afternoon.

A gale warning is in effect across the ocean waters Thursday through Friday, for wind gusts up to 40 knots and ocean seas up to 15 feet or more, the hurricane center said. Dangerous conditions are expected around inlets and the entrance to eastern Long Island Sound. A small craft advisory remains in effect through Thursday evening.

Rich Borawski, lifeguard chief at Long Beach, said the water was closed to all bathers Wednesday, but open to surfers and Boogie boarders wearing fins due to dangerously high rip currents.

Borawski said that surfers are authorized to be in the water because their boards act as a flotation device, which can be a lifesaving tool if caught in a rip current.

"If a surfer wipes out, they're attached to the board with their leash," he said. "Where the bather starts body surfing, they can get hurt and get caught in a rip in a moment's notice."

Boogie boarders will not be allowed in the water without fins to maneuver out of dangerous waters, as a Boogie board acts as a weaker flotation device compared to a surf board, he added.

"Unless you're an Olympic swimmer, it's going to be very difficult for you to be in this water without any type of fins," Borawski said.