This will be another sweltering day ripe with potential dangers, the National Weather Service warns.

The heat index, measuring the combined impact of the temperature and humidity, will again crest at the 100-degree mark -- or higher. As a result, there is a heat advisory in effect till 8 p.m.

There is also an air-quality alert -- warning of potentially unhealthy ozone levels -- in effect indefinitely.

Scattered storms are possible this afternoon and tonight, and some of them could be severe, the weather service warns in a "hazardous weather outlook."

The heat wave gripping southwestern Connecticut is likely to continue another day or two, as under sunny skies, with daytime high temperature will rise to the mid-90s today, but the heat index values will make it feel as though it is 100 degrees or more. The odds of daytime precipitation -- potentially, scattered thunderstorms -- are about 30 percent after 3 p.m.

Tonight, there remains a 30 percent chance of scattered showers and thunderstorms, mainly before 11 p.m. Night skies will be partly cloudy, with a low temperature in the mid-70s.

On Friday, there is a 20 percent chance of isolated showers and thunderstorms after 2 p.m. Otherwise, skies will be mostly sunny, with a high temperature in the mid-90s. Nighttime will be partly cloudy, with a low temperature in the mid-70s.

Saturday brings increased odds of unsettled weather as cooler air begins to move into the area. There is a 50 percent chance of showers and thunderstorms, mainly after noon, the NWS says, the temperature rises to a high near 90 degrees.

Showers and thunderstorms are likely Saturday night -- odds are 70 percent -- as the temperature dips to about 70 degrees.

Sunday is expected to be partly sunny as the region begins to cool off a bit, with a daytime high temperature in the mid-80s. Night skies will be partly sunny with a low temperature in the mid-60s.

The outlook for Monday, according to the weather service, is partly sunny and temperatures rising to about 80 degrees.