As Hurricane Arthur continues its course northward off the New England coast, wind gusts as high as 62 miles per hour were observed on Nantucket Island, according to the National Weather Service.
There were also reports of flooding on the island around Broad and Easy streets.
The weather service said in an advisory issued shortly before 9:30 that rain is expected to come to an end over the next few hours.
The storm has been dumping buckets of rain on Massachusetts for much of the day and could inundate some areas with up to 10 inches of rain.
As Arthur steams through the ocean towards the state, "the biggest problem would be the rain and the flash flooding with that rain," said weather service meteorologist Bill Simpson. He said the rain was expected to fall the hardest on the South Coast.
Forecasters said the torrents could pour down at a rate of 3 inches per hour, and they expected numerous flash floods. Many areas are expected to get a total of 3 to 6 inches, while others could get 7 to 8, or even 10, forecasters said.
The rain will taper off overnight from west to east, ending in western portions of the state around 11 p.m. and in eastern portions about 3 or 4 a.m. Saturday, according to a forecast discussion posted on the Web by the weather service.
At about 11 p.m., the weather service fielded reports of 8 inches of rain in New Bedford, 5.73 in Fairhaven, and 4.5 in Acushnet.
Forecasters issued flash flood watches and warnings, saying the flooding from small streams or in urban poor drainage areas was potentially life-threatening.
"Don't drive on flooded roads," said weather service meteorologist Rebecca Gould, "because you don't know how deep the water is or if the road is even still there. Traveling is probably not going to be ideal this afternoon for that reason."
Numerous roads in Southeastern Massachusetts were flooded and impassable this afternoon, some with more than a foot of water, according to reports collected by the National Weather Service. The highest number of reports came from hard-hit New Bedford, but flooding was also reported in Westport, Dartmouth, Fairhaven, Freetown, Wareham, and Plymouth.
State Police said they had closed Exit 15 on I-195 northbound and southbound in New Bedford, and Route 18 southbound to Route 6.
In Fairhaven, Adams Street was flooded and blocked off, according to residents.
"I've been in this house 26 years. This is the first time I've ever seen my street flooded like this," said Maria Fumo, 64. "My backyard, oh my God! I had to go outside, I couldn't believe it. It's like quicksand."
Cars create waves driving down the street, she said, and she had instructed her husband to stay at her daughter's house with the family van, which rides low and is prone to flooding.
Early in the afternoon, said Fumo, her foster daughter was waiting by the open front door for her boyfriend when a bolt of lighting flashed in the door.
"Knocked her down and came halfway into the kitchen!" said Fumo. Fumo's daughter was knocked back against a table, but was all right.
"I don't like it. I'm scared," said Fumo.
The forecasters also warned of tropical storm conditions, with winds of 40 miles per hour or more, on both Cape Cod and Nantucket. The center of Arthur is passing southeast of New England.
At 8 p.m., Arthur was moving northeast at 28 miles per hour with maximum sustained winds of 80 miles per hour, the weather service said. The storm was a Category 1, the weakest kind, having been downgraded earlier this morning from Category 2.
The hurricane was expected to accelerate and race up the coast, while its winds weaken, the forecasters said. After slipping by Massachusetts, the storm will continue northeast, toward Nova Scotia.
Forecasters warned mariners that winds from Arthur will whip up dangerously high seas off the coast. They issued a hurricane warning for some portions of costal waters and tropical storm and gale warnings for other portions.
"Wind will be the main concern across the coastal waters and immediate coastal areas," forecasters said in a tropical storm warning. "Heavy rain will be the primary concern inland. Coastal areas will also be at risk for high surf and dangerous rip currents."
Small craft should remain in port and well secured, the warning said.
The forecasters cautioned that even though other coastal areas of the state are not under tropical storm watches or warnings, people there should still beware of impacts from the storm.
One piece of good news: Forecasters said they were not overly concerned with coastal flooding because Arthur will be pulling away from the coast quickly and tides will be relatively low. They predicted a storm surge of 1 to 2 feet possibly in Nantucket Harbor. They also warned that erosion is possible on the east and south shores of Nantucket as well as the ocean side of Cape Cod.
Still, Gould said, rip currents could remain a sneaky hazard, possibly through the weekend.
Beachgoers should beware of deceptively safe-looking water when they venture out Saturday after the weather improves, she said, because it still might be concealing rip currents.
The unsettled weather today comes after a parade of thunderstorms rumbled through the state Thursday, bringing down trees, branches, and power lines. An apparent microburst uprooted trees and utility poles and brought down wires in Methuen. Lightning from the storms may have played a role in starting two fires, in homes in Shutesbury and Ayer, according to reports fielded by the weather service.
Weather service forecasters said it appeared that microbursts had happened in several other communities as well.
Thousands of people were drenched by rain as thunder boomed and lightning flickered in the sky when a storm hit Boston Thursday night just after organizers of the Boston Pops concert and fireworks display rushed to finish their show.
Evan Allen of the Globe staff contributed to this report.