Update: The National Weather Service issued a severe thunderstorm warning for Taunton, Attleboro, and Bridgewater until 5:30 p.m.


National Weather Service has issued a severe thunderstorm watch for most of Massachusetts, saying there is the potential for strong to severe storms that will dump heavy rain and whip up strong strong winds from about 3 p.m. to 9 p.m. Monday.

Strong thunderstorms were rolling through Central Massachusetts by midafternoon. The weather service fielded reports of trees and wires down in Western and Central Massachusetts — and a report that in the Agawam area hail fell that was the size of golf balls.


Forecasters said the greater Boston area is expected get hit between 4:30 p.m. and 5:30 p.m.

The storms are rolling toward the city as the state simmers in stifling heat. The temperature at Logan International Airport was at 93 degrees at 2 p.m.

The National Weather Service has issued a heat advisory from 11 a.m. to 8 p.m. for parts of Norfolk, Middlesex, Bristol, and Plymouth counties.

“Drink plenty of fluids, stay in an air-conditioned room, stay out of the sunshine, and check up on relatives and neighbors,” forecasters from the weather service said early Monday.

Areas of Western Mass., specifically Hampden County, and much of Connecticut will also be under a heat advisory during the middle parts of the day, with similar heat index levels, which forecasters predict will top out around 96 degrees.

“The Heat Advisory for today has been expanded to include portions of eastern MA along with the Hartford to Springfield corridor,” forecasters tweeted. “Heat index values are expected to climb into the mid to upper 90s today.”

“Heat index” is a measure of how hot it feels outside with air temperature and relative humidity combined. Monday is expected to be a fairly humid day, with a dewpoint reaching into the 70s.


Martin Finucane of the Globe staff contributed to this report. Peter Bailey-Wells can be reached at peter.bailey-wells@globe.com. Follow him on Twitter @pbaileywells.