From the National Weather Service:
Severe Weather Potential Monday through Monday Night (info as of 7:30PM 6/18/17)
The National Weather Service (NWS) is forecasting an active period of hazardous weather starting tomorrow (Mondy) afternoon and lasting through late tomorrow night. Western Massachusetts has been placed at an enhanced risk, central Massachusetts at a slight risk, and eastern and southeastern Massachusetts at a marginal risk for severe weather. Numerous showers and thunderstorms with areas of torrential rainfall are expected to overspread the region starting in the mid to late afternoon hours tomorrow and continuing well into the overnight hours, possibly accompanied by damaging winds, hail, and possibly even an isolated tornado.
A Flash Flood Watch is currently in effect for Berkshire, Franklin, Hampden, Hampshire, Worcester and northern Middlesex Counties through 4:00 AM Tuesday.
• Up to 2-3 inches of rain are forecast to fall in western Massachusetts through late Monday night, with lower amounts to the south and east.
• Rainfall rates in excess of 2 inches per hour are possible where persistent heavy rainfall occurs or where thunderstorms repeatedly move over the same areas, resulting in localized flash flooding and significant flooding in urban/poor drainage areas, and potential impacts to the Monday evening commute.
• 40-60 MPH wind gusts are expected with the strongest storms. Tree damage, scattered power outages, and isolated damage to structures are possible.
• Up to quarter-sized hail is possible, which may result in isolated property damage.
• Frequent cloud-to-ground lightning may be associated with the strongest storms.
• There is a possibility of an isolated tornado.
Thunderstorm and Lightning safety information:http://www.mass.gov/mema/thunderstorms