Flash flood warning for Mass. today, but drier air, sunny skies expected later this week

By Jasper Craven, Globe Correspondent

The rain won’t relent today, with a flash flood watch in effect for all of Massachusetts until 8 p.m. Temperatures will climb into the high 70s, with humid conditions lingering until this evening, according to the National Weather Service.

“This evening and overnight a cold front is going to move across the state, and that’s going to introduce a drier, cooler air mass,” said meteorologist Charlie Foley. “We won’t have this soupy moisture for much longer.”

Heavy showers and thunderstorms — and some tropical downpours — could bring 2 inches of rain to Boston early this afternoon, and some regions could see more precipitation.

Heavy rain has already saturated the ground across the Bay State, heightening the chances for flash flooding of roads, streams, and creeks, according to the weather service. Franklin County has already recorded more than 4 inches of rain this morning, Foley said.

The chance of showers and thunderstorms will diminish this evening, with temperatures dropping slightly into the low 70s and dewpoints remaining in the upper 60s. A cold front will sweep across the region late tonight, setting up for a cool, mostly dry Wednesday.

Wednesday will see temperatures in the mid-80s, with a mix of clouds and sunshine. The cold front will bring diminished dewpoints in the 50s. Scattered showers and thunderstorms are possible Wednesday, and are most likely in Southeastern Massachusetts. Boston has a 20 percent chance of precipitation for Wednesday, according to the weather service.

Thursday and Friday will remain mostly dry and sunny, with low humidity levels and temperatures unlikely to break 80 degrees. Temperatures will rise a few degrees on Saturday, but conditions will remain pleasant and seasonable.

Sunday could see some more precipitation that could bleed into Monday, with next week likely to remain comfortable and warm.

“We certainly won’t see the heat we saw in the recent past for next week,” Foley said, alluding to the record-setting heat wave that lasted seven days.

Jasper can be reached at jasper.craven@globe.com or on Twitter @Jasper_Craven