Jacob Gaertner, 11, cools off at Geiger Park in Wyandanch...

Jacob Gaertner, 11, cools off at Geiger Park in Wyandanch on Tuesday. Forecasters say Long Island should prepare for the possible effects of Hurricane Elsa by late Thursday. Credit: Newsday/Alejandra Villa Loarca

After severe thunderstorms and high winds rumbled across Long Island Tuesday night, more foul weather could be on the way, courtesy of Hurricane Elsa, which may bring heavy rains and dangerous rip currents later in the week.

Heavy rain leftover from the Tuesday night's storms triggered flash flooding in some parts of southern and central Suffolk, the National Weather Service said.

PSEG Long Island reported that about 6,000 customers had lost power as of 8:39 p.m. PSEG reports crews were out working to restore customers "safely and as quickly as possible," spokeswoman Ashley Chauvin said. Just after 1 a.m. Wednesday, 2,274 customers remained without power, according to the PSEG Long Island website.

At the airports, Long Island MacArthur Airport had no departure and arrival flight delays, according to FlightAware, a website that tracks air traffic. At John F. Kennedy International Airport, arrival flights were delayed up to 30 minutes, while departures flights were delayed for up to two hours due to the weather, the aviation website reported.

Some flights headed into JFK Tuesday were diverted to other airports such as Atlantic City.

At LaGuardia Airport, departures were delayed for up to an hour and 45 minutes, while arrivals were delayed for up to an hour.

Dominic Ramunni, a meteorologist with the National Weather Service, said there could be "some dry weather overnight before we potentially do it again later on tomorrow afternoon and evening, where we see another chance of some showers and thunderstorms."

The weather service also warned that Tropical Storm Elsa could affect Long Island later in the week.

Late Tuesday, the National Hurricane Center was tracking Elsa 65 miles southwest of the Tampa Florida coast as it churned north at 14 mph with wind gusts clocked at 75 mph. The storm is predicted to possibly affect Long Island Thursday night into Friday, the weather service said in a briefing.

Elsa could bring heavy downpours with 1 to 3 inches of rain, flash flooding, high surf, beach erosion and dangerous rip currents, forecasters said.

A heat advisory has also been issued for almost all of the tristate area — with just a few exceptions, including eastern Suffolk. That advisory expires at 8 p.m. Wednesday.

Heat indexes that trigger these warnings measure the impact of heat plus humidity. Temperatures on Long Island hit a high of 88 degrees in many areas Tuesday afternoon, although it felt much hotter.

Wednesday’s predicted high is 91 degrees but it should feel as hot as 100 degrees. Storms are predicted to sweep through again in late afternoon and begin a cooling trend but are more likely to be stronger north and west of New York City, the weather service said.

Then Thursday night, here comes Elsa.

With David Olson