The severe winter storm sweeping across southwestern Connecticut on Sunday night has morphed into a quadruple threat, according to the National Weather Service.

The day-long snow storm, driven by blustery winds, is expected to continue battering the region overnight and into Monday afternoon, prompting the NWS to issue four bulletins Sunday night: a Blizzard Warning, a Coastal Flood Warning, a Special Weather Statement on the intensity and duration of the storm, and a Hazardous Weather Outlook.

Dangerous blizzard conditions will take hold tonight, according to the forecast, with bands of heavy snow surging through the area that may produce accumulation rates of 1 to 2 inches an hour, and as much as 2 to 4 inches an hour at some points, the NWS warns.

The snow will be driven by a north wind, with gusts increasing to 20 to 30 mph.

Overall snow accumulation by Monday could be as much as 15 to 20 inches, the weather service predicts.

This day-after-Christmas storm has wreaked havoc with travelers heading home after the holiday.

NWS forecasters have issues a "Blizzard Warning," "Coastal Flood Watch" and "Hazardous Weather Outlook" for southwestern Connecticut, which all will remain in effect until Monday evening.

Overnight temperatures are expected to plunge to the mid-20s.

The storm should slow by Monday morning, with light snow mainly before noon. It will be cloudy, with a high near 33. There will be a north wind around 30 mph, gusting as high as 47 mph.

By Monday night, the storm will have cleared through the region, but it will be very cold with a low temperature of about 20 degrees. It will also be windy, with a northwest track between 18 and 26 mph, with gusts as high as 39 mph.

Tuesday is expected to be mostly clear, with a daytime temperatures in the mid-30s.