Hazardous weather on Long Island with thunderstorms, heavy rain as air quality remains unhealthy

Heavy rains and thunderstorms rolled in Saturday afternoon as air quality remained low on Long Island.

The National Weather Service issued a hazardous weather outlook announcement for southern Nassau and Suffolk counties, warning of periods of heavy rain and high winds.

The weather service warned Saturday afternoon of "torrential" rain moving east at 40 mph from Melville. The service reported "frequent" lightning strikes and warned the winds could cause falling branches. People in the path of the thunderstorm — predominantly those in western and central Suffolk — were advised to take shelter indoors.

A flood advisory was also issued for western Suffolk County until 4 p.m.

There will be "multiple rounds of thunderstorms" Saturday through early afternoon, and again in the later afternoon and evening, NWS meteorologist Bill Goodman said.

There could be "quick downpours" of an inch or two, damaging winds and even the slight possibility of a tornado, Goodman said. It's not likely, he said, but "it's not zero." 

The NWS issued a flash flood warning for Brooklyn, Manhattan, Queens, Staten Island until 2 p.m. Saturday, as heavy downpours are expected to flood streets and other low-ling areas. Residents there were advised to leave basements and retreat to higher floors and not to drive through flooded streets.

Nassau County closed all county-run beaches and outdoor swimming pools Saturday because of the poor air quality and threatened storms and the risk of flash floods. The indoor pool at Eisenhower Park remained open, county officials said. The NWS warned of dangerous rip currents on the entire South Shore through Saturday.

Air quality was rated unhealthy by the Department of Environmental Conservation across most of Long Island, and moderate at the East End. 

Visibility was low Saturday, but the heavy rains are expected to "scour things out" by the end of the day, Goodman said. 

Drivers should avoid traveling during these heavy storms, the state Department of Homeland Security advised. Those who are on the road during the heavy rains are advised to slow down, keep both hands on the wheel and never drive through flooded roads.

Some outdoor concerts and other events scheduled for Saturday were cancelled because of the coming thunderstorms.

The "Simply Stapleton" concert scheduled for tonight at the Harry Chapin Lakeside Theater in Eisenhower Park was postponed; the new date is August 4 at 7 p.m.

An Independence Day celebration in Huntington, featuring a reenactment of the first time the Declaration of Independence was read on Long Island, was rescheduled for Sunday. 

A series of wildfires in Ontario and Quebec has blanketed regions throughout the Midwest and Northeast with smoke.

For at least part of Saturday, air quality will remain unhealthy for all groups, the DEC said. Residents, particularly young children, seniors and those with health conditions, should limit time outside and report any serious irritation, shortness of breath or chest pain to a doctor, said Suffolk County Department of Health Services Commissioner Dr. Gregson Pigott.

"We expect rain to bring some much-needed relief to New Yorkers experiencing poor air quality over the weekend, but with it we may see the possibility of severe storms," Gov. Kathy Hochul said in a statement Friday evening. "I remind everyone to take this weather seriously: Take precautions, know what to do if a storm reaches your areas and remember to stay air quality aware to protect your health."

On Sunday, the weather will improve markedly, with near pristine conditions and highs in the low 80s expected. Skies will start partly to mostly cloudy but gradually become sunny due to northwest winds — all possibly in time for the 3 p.m. start of the World Cup final between Argentina and Spain at MetLife Stadium in New Jersey.

Sunny weather with highs in the mid-80s should continue into Monday and Tuesday, the forecast said.

How is the air quality today?

When will the air quality get better on Long Island?

A frontal system coming in this weekend could alleviate the air quality conditions, said meteorologist Jay Engel.

"We’re looking for some improvement on the air quality on Sunday," Engel said.

What are the health effects of the smoke?

People with breathing problems need to be especially cautious, as well as people who work outdoors. But studies have found that wildfire smoke can also effect cognition. Here's what to know and how to stay safe.

Newsday's John Asbury contributed to this story.