An historic amount of rain fell in parts of Massachusetts Thursday, unleashing floods in towns south of Boston.

Boston is in for a muggy humid, hot week, according to National Weather Service forecasts, with more flooding possible as the week goes on.

A "considerable" flash flood warning was issued in Boston on Thursday morning as heavy rain pounded the city and areas to the south.Four to 6 inches of rain fell in the towns of Canton, Quincy and North Scituate.

Thursday's rain was a highly localized event. The highest impact was only felt over a 5-to-10 mile area south of Boston.

This week in the Boston Globe Weather Mailbag, Globe Weather HQ tackles questions surrounding summer thunderstorm frequency, the best weather reporting station, air quality categories, and the HAARP model, most commonly used in Aurora forecasting.

Several Massachusetts communities south of Boston received as much as over 5 inches of rain, with flooding closing several streets and parts of Interstate 93.

Flash floods hit cities and towns south of Boston Thursday as historic rain brought traffic to a crawl and shut down part of I-93.

Boston's weather forecast includes sunny conditions, a heat wave, and chances of thunderstorms, with high humidity and advisories expected midweek.

Communities south of Boston have seen as much as 4 and a half inches of rain, with a flash flood warning still in effect.

Boston, Quincy, Brockton, and other South Shore communities are under a flood watch until 9 a.m., according to the National Weather Service.

The flooding necessitated rescues, grounded planes, and submerged vehicles in waist-high water less than two weeks after flash floods in Texas killed more than 100 people, triggering concerns about the increasing number of flood fatalities in recent years because of heavier rainfall,