With rain coming down so fast, storm drains couldn't handle the deluge of water. On Interstate 93 in Quincy, all were lanes closed at one point because of extreme flooding during rush hour. At least five cars were stuck on the highway until the water receded.

The agency predicted rain would fall at a rate of 1 to 2 inches per hour, potentially overwhelming small creeks and streams, streets, highways and underpasses, as well as other poor drainage and low-lying areas.

On Thursday at 6:01 a.m. the National Weather Service released a flash flood warning in effect until 9 a.m. for Bristol, Middlesex, Norfolk, Plymouth, Suffolk and Worcester counties.