LEOMINSTER, MASS. -- Hurricane Lee looks poised to wallop New England later this week even as the region still deals with the impact of days of wild weather that produced torrential rain, flooding, sinkholes and a likely tornado.

A hurricane watch stretches from Stonington, Maine to the U.S.-Canadian border, where hurricane conditions, heavy rainfall and coastal flooding are possible Friday night and Saturday, the National Hurricane Center said Wednesday night.

Areas from Watch Hill, Rhode Island, to Stonington, Maine -- including Block Island, Martha's Vineyard and Nantucket -- are under a tropical storm watch. A storm surge watch has also been issued for Cape Cod Bay and Nantucket with the potential for life-threatening flooding there late Friday and Saturday.

The looming arrival of the hurricane threatened to unleash more violent storms on a region that earlier in the week saw 10 inches (25 centimetres) of rainfall over six hours and on Wednesday saw communities in Massachusetts and Rhode Island deal with tornado warnings and more heavy rain that opened up sinkholes and brought devastating flooding to several areas.

The National Weather Service in Boston said radar data and videos showed it was likely that a tornado damaged trees and power lines in Rhode Island and Connecticut on Wednesday. In Lincoln, Rhode Island, photos after the storm showed at least one roof damaged and the press box at the high school stadium tipped into the bleachers.

Rhode Island Gov. Dan McKee said on social media that the state's emergency operations centre was activated and would be monitoring the fast-changing weather conditions over the next few days.

"The best thing you can do right now: Stay tuned for frequent updates," McKee said.

In North Attleborough, Massachusetts, which was hit by heavy flooding Monday night, Sean Pope watched the forecast with unease. Heavy rain turned his swimming pool into a mud pit and filled his basement with 3 feet (91 centimetres) of water.

"I am hanging on, hoping and watching the forecast and looking for hot spots where it may rain and where there are breaks," he said. "We have to make sure the pumps are working."

Late Tuesday, Massachusetts Gov. Maura Healey issued a state of emergency following the "catastrophic flash flooding and property damage" in two counties and other communities. The torrential downpour in a six hour period earlier in the week was a "200-year event," said Matthew Belk, a meteorologist with the National Weather Service in Boston.

Healey said Wednesday that the state's emergency management agency is watching the weather and is prepared to offer assistance. The state is monitoring the conditions of dams, she said, and she urged residents to take flood warnings seriously and to stay off the roads when ordered.

The rain created several sinkholes in Leominster, Massachusetts, including one at a dealership where several cars were swallowed up. In Providence, Rhode Island, downpours flooded a parking lot and parts of a shopping mall. Firefighters used inflatable boats to rescue more than two dozen people stranded in cars.

After a dry day, it started raining in Leominster again Wednesday afternoon. Parts of Massachusetts and Rhode Island were under a flash flood warning. Earlier in the day, there were heavy downpours in Danbury, Connecticut, where officials said they had to rescue several people from vehicles stuck in floodwaters.

Rain from Hurricane Lee didn't contribute to the flooding earlier this week. But the hurricane is traveling north and could make landfall in Nova Scotia, Canada, possibly as a tropical storm, forecasters said.

"The ground is saturated. It can't take in anymore," Leominster Mayor Dean Mazzarella said at a news conference Wednesday.

Mazarella said up to 300 people were evacuated by Tuesday morning in the city, which has not seen such widespread damage since a 1936 hurricane. Most buildings downtown flooded and some collapsed.

He said early estimates on city infrastructure restoration projects could be anywhere from $25 million to $40 million.

New England has experienced its share of flooding this summer, including a storm that dumped up to two months of rain in two days in Vermont in July, resulting in two deaths. Scientists are finding that storms around the world are forming in a warmer atmosphere, making extreme rainfall a more frequent reality now.