The National Weather Service issued a flash flood warning for Boston and areas surrounding the city on Saturday as a stalled frontal boundary dumped heavy rain on the region.
The warning was issued at 2:41 p.m. and is set to expire at 5:45 p.m., according to a weather service bulletin. The rainy conditions extend the streak of wet weather to 13 weekends in a row, said Ken Mahan, the Globe’s lead meteorologist.
“Multiple areas are seeing multiple rounds of heavy rain,” he said Saturday. “This is the result of multiple days of above-average temperatures with above-average humidity priming the atmosphere.”
The weather pattern covers much of New England, Mahan said, stretching south to Providence and Hartford, west to the Berkshires and north to southern New Hampshire and coastal, southern Maine.
Thunderstorms have dropped 1 to 2 inches of rain and caused street flooding across portions of Middlesex County, and rain is forecast to fall at a rate of 1 to 2 inches per hour, the weather service said.
The heavy rain creates risks of ponding on roads, low visibility, and overflowing creeks and rivers in low-lying areas, according to Mahan.
The weather service said the public shouldn’t attempt to drive on flooded roads.
“Turn around, don`t drown when encountering flooded roads,” the agency said in its bulletin. “Most flood deaths occur in vehicles.”
The wet conditions are expected to last through sunset before drying out, beginning at about 8 p.m., Mahan said.
Conditions are expected to improve for Sunday, which Mahan described as a “gorgeous day” with sunny skies and temperatures in the 70s.
Laura Crimaldi can be reached at laura.crimaldi@globe.com. Follow her @lauracrimaldi.
