The National Weather Service issued a flood advisory Wednesday, in effect until 5:30 p.m., for west central Suffolk County and central Nassau County as "radar indicated heavy rain due to thunderstorms."
It was otherwise mostly cloudy on Long Island.
There is also a high rip current risk for ocean beaches through Wednesday afternoon, the weather service said.
High temperatures are expected to be in the mid- to upper 70s, the weather service said.
It will be warm and humid, said News 12 Long Island meteorologist Rich Hoffman, but "not a washout."
Thursday and Friday will have highs in the mid-70s, forecasters said. There will be a chance of more showers and thunderstorms before noon Thursday.