After a picture-book summer weekend, a third warm and sunny day is on tap for southwestern Connecticut, according to the National Weather Service.

But there are storm clouds on the horizon, the NWS warns.

Skies will be mostly sunny, with a daytime temperature rising to the upper-80s.

Overnight, there is a slight chance of showers and thunderstorms after 2 a.m. Skies will be mostly cloudy, with a low around 73 and a south wind between 9 and 11 mph.

Conditions tomorrow afternoon has triggered a hazardous weather outlook from the NWS.

An approaching cold front then could trigger thunderstorms, some of which could be severe with heavy rain, strong winds and even hail. After the threat of stormy weather passes later tomorrow night, the temperature is expected to fall to a low of about 70 degrees.

The outlook clears Wednesday, which is expected to have sunny skies with a high of about 80, the weather service predicts.