Most of the commonwealth's homless shelters are already operating at reduced capacity. Now they could be overwhelmed by impending winter weather, the latest surge in COVID-19 cases and a potential wave of evictions, according to shelter operators, advocates and local officials.

Many say they are already seeing more people living outside than at any time in recent memory — whether alone, in small groups of tents on city streets or in larger encampments, often on the fringes of urban centers.

Bruce, a man in his late thirties who has been homeless on and off for years, is one such person. Speaking to GBH News at MBTA’s Alewife station, where he was preparing to spend a recent night, Bruce recounted trying to go to the CASPAR emergency shelter in Cambridge and being turned away because the shelter was full.

“They basically said, 'You might as well try Boston,'” Bruce said.

GBH News couldn’t confirm the details of Bruce's story, but it is hardly unique.

In the early days of the pandemic this spring, COVID-19 infections among shelter guests surged to as high as 30% or more.

To stem the spread of the virus, shelters “de-populated,” cutting bed capacity by as much as half in some cases.

At the time, the loss of capacity was mitigated by various means, including dedicated treatment and isolation space in field hospitals and large outdoor tents in Boston and Worcester, along with the use of hotel rooms and other more ad hoc measures.

But most of those measures were temporary. And with winter weather arriving, shelter operators have been clamoring for months for additional emergency capacity.

State officials have acted on those calls in recent weeks. Officials for the state's Department of Housing and Community Development say they've secured over 1,000 extra emergency shelter beds statewide.

Some cities have stepped up too: Boston officials say they've added more than 200 beds for this winter and are hoping to add over 300 more in the near future. In Cambridge, an overnight "heating center" is now open around the clock. Officials in Worcester and Quincy say they're ready to utilize motel rooms if needed.

But the question remains whether that added capacity will be sufficient, given extraordinary uncertainty about the needs in this unpredented time.

“We know that there have been encampments growing in an unparalleled fashion here in Massachusetts around all of the various communities, from Pittsfield to the Cape,” said Joe Finn, president and executive director of the Massachusetts Housing and Shelter Alliance.

Jim Stewart, who runs the First Church shelter in Cambridge, agrees.

“People have slept on the subways for 100 years,” Stewart said. “But now you have people … basically camped on the benches at stations around there, not just overnight but 24 hours.”

Other shelter operators and advocates for the homeless describe seeing more people on the street or living in encampments in Brockton, Lowell, Waltham, Brockton, Quincy and Lawrence.

The reasons for the apparent trend aren’t clear. Experts who spoke with GBH News speculated that there could be a variety of factors at play, from reduced capacity at overnight shelters to more people becoming homeless from having lost jobs in the pandemic, to legitimate concerns about the risks of exposure to infection inside shelters.

It’s also possible that the pandemic itself has simply made people already living outside more visible, said Cassie Hurd, who runs the Material Aid and Advocacy Program in Cambridge and regularly visits people living outdoors.

When shelter-at-home orders took effect at the start of the pandemic, “They were kind of the only people left out on the street,” Hurd pointed out.

Visibility, Hurd said, has often meant trouble.

“It seems like there’s an increase in [police] moving people along, breaking up encampments and sweeping encampments because people are so hyper-visible,” Hurd said.

Hurd points to guidelines from the Centers for Disease Control and Prevention suggesting that with infections still surging, living outdoors may, in fact, be safer than alternatives. The CDC has urged local officials to carefully weigh the risks of displacing people who do so.

Dr. Jim O’Connell, president of Boston Health Care for the Homeless Program, said that living outdoors carries severe health risks, but that right now, given the potential for transmission of COVID-19 indoors, “allowing the encampments to be is probably safer during these immediate times."

“Does that mean it's good policy long term? No, not at all," he told GBH News. "But I think these are just extraordinary times, and we probably have to have exceptions.”

Those sentiments are echoed by Terri, a woman who had been living in a tent on a plaza with a half dozen or so other people near Boston’s South Station for the past two or three months.

Terri told GBH News she’s been in and out of shelters, and what she really wants is a home.

For now, though, she said the encampment felt like the best option and offered her “a community that looks out for each other.”

After last week's snowstorm, Terri called to say she and the others had been forced to pack up and leave.

She was at South Station, she said, and didn’t know where she was going to go next.