A tornado warning was issued for Plymouth and Bristol counties, as well as on the Cape and Islands until 12:45 a.m. on Thursday, according to the National Weather Service.
A tornado watch was also issued for parts of Massachusetts and Rhode Island until 7 a.m. Thursday, forecasters said.
Residents in areas under the tornado warning were told to take shelter in a basement or on the lowest level of a sturdy building, according to an alert from the Federal Emergency Management Agency.
The remnants of Hurricane Ida will dump up to 8 inches of rain on Southern New England on Wednesday into Thursday, forecasters said, bringing the threat of flooded roads and inundated basements.
“The potential for very significant urban and small stream flash flooding exists as well as the possibility of significant river flooding,” forecasters said in a flash flood watch.
A widespread 3 to 5 inches of rain is expected. While the “axis of heaviest rainfall remains uncertain, areas near and south of the Massachusetts Turnpike appear to be at greatest risk,” the flood watch said.
The overnight downpours are likely to cause dangerous driving conditions during the morning commute Thursday and could lead to washouts and closed roads in some areas, forecasters said.
“Heavy rain will reduce visibility and will make driving pretty tough,” said Kristie Smith, a meteorologist with the National Weather Service in Boston. “The roads will be slick, and hydroplaning is always a problem when we get heavy rain.”
The showers are expected to taper off around noon on Thursday, she said.
“Luckily this is a progressive system, meaning it will move out quickly,” Smith said. “We should have blue skies and a nice sunset [Thursday] evening.”
With streams already running high from recent rains, there is “very little capacity left for an excessive rainfall event,” forecasters said. “This will yield widespread flooding with very significant to rare/high end flooding where 6 to 7 inch amounts materialized.”
“There’s just nowhere for this water to go,” Smith said.
The National Weather Service issued a flash flood warning in central Massachusetts for Springfield, Chicopee, and Westfield until 5 a.m. Thursday.
In addition to the downpours, forecasters warned of severe thunderstorms and a risk of tornadoes in Southeastern Massachusetts and southern Rhode Island.
According to projections, Boston could receive up to six inches of rain, as could communities in Norfolk, Plymouth, and Bristol counties as well as Providence, Newport, and Coventry, R.I., by late Thursday. “Widespread torrential rainfall” was expected to arrive in Rhode Island and Eastern Massachusetts between 10 p.m. and 2 a.m. Thursday.
There is some good weather news ahead for Friday and Saturday.
“Drier conditions behind the remnants of Ida to start the holiday weekend,” forecasters wrote. “High pressure builds in behind the remnants of Ida on Friday, bringing sunny skies and early fall-like conditions to southern New England. Afternoon high temperatures likely to top out in the mid to upper 70s on these days.”