State issues air-quality alert amid heat, humidity

By Melissa M. Werthmann, Globe Correspondent

Ozone levels across Massachusetts could reach unhealthy standards today, prompting the Department of Environmental Protection to issue an air-quality alert for the state.

A high-pressure system combined with a weak cold front will produce intense heat and humidity today with a southwesterly breeze, DEP officials said. The breeze will carry pollutants across the Bay State and spur ozone formation.

The DEP’s air-quality hotline reported that the air quality is expected to produce ozone readings that climb “into the range that we’d consider to be unhealthy for sensitive people,” such as those with asthma or other respiratory problems.

Temperatures are expected to climb into into the low 90s, according to the National Weather Service.

Scattered showers and thunderstorms could pop up around the state this evening, said meteorologist Charlie Foley.

He said the air mass hovering over the state is very unstable, and predicted that Boston residents could see raindrops as early as 2 p.m. The chance for wet weather continues into the evening, and the area with the greatest risk for storms is north of the Massachusetts Turnpike, Foley said.