Unsettled weather Friday through the weekend; ozone alert ends Wednesday night

An air quality alert will be in effect most of Wednesday for Long Island and New York City as ground-level ozone is expected to hit levels considered unhealthy for sensitive groups, and the region could experience some severe weather including possible flash flooding later this week.

The New York State Department of Environmental Conservation sent out the air quality advisory, which is effective until 11 p.m. Wednesday.

As of 3:30 p.m., air quality was considered "moderate" in many parts of Long Island and "unhealthy for sensitive groups" in other parts. The ozone level is expected to be lower Thursday.

Meanwhile, the National Weather Service warns that there is a "marginal risk" the area could experience "severe weather" with heavy rain, thunderstorms and flash flooding possible, off and on, from Thursday night right through Sunday night. Up to an inch of rain is forecast with possibly higher amounts in some localities.

During those storms, Long Island could see wind gusts in excess of 58 mph Friday that could damage trees and power lines and result in scattered power outages, according to the forecast. There's also the possibility of hail.

Thursday, during the day, is expected to be sunny, with a high of 87 and a heat index of 95. Highs Friday and over the weekend were predicted to be the low to mid 80s, the weather service said, but humidity was expected to be high.