From the National Weather Service:
Flood Watch National Weather Service Boston/Norton MA 124 PM EDT Wed Jul 17 2019 124 PM EDT Wed Jul 17 2019 ...FLASH FLOOD WATCH IN EFFECT UNTIL 11 PM EDT THIS EVENING... The National Weather Service in Boston/Norton has issued a * Flash Flood Watch for portions of northern Connecticut, Massachusetts, and Rhode Island. * Until 11 PM EDT this evening. * Numerous showers and thunderstorms are expected to develop during the mid to late afternoon hours and continue into the evening. The stronger thunderstorms will be capable of producing torrential rainfall with localized rainfall amounts exceeding 2 inches in just an hour. This will result in the potential for localized flash flooding, particularly if this were to occur in an urban center. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Flash Flood Watch means that conditions may develop that lead to flash flooding. Flash flooding is a very dangerous situation. You should monitor later forecasts and be prepared to take action should Flash Flood Warnings be issued.