California looked like it was opening back up ... and then it wasn't.

Gov. Gavin Newsom on Wednesday announced the closure of many commercial indoor activities in 19 counties, including Contra Costa, Santa Clara and Solano counties in the Bay Area. All bars, indoor restaurants, movie theaters, wineries, museums, family entertainment centers, zoos and card room gambling businesses will be closed in those counties for at least three weeks.

This move is prompted by an alarming jump in COVID-19 cases and hospitalizations, and seeks to limit the transmission of the coronavirus in indoor spaces.

"The bottom line is: The spread of this virus continues at a rate that is particularly concerning," Newsom said.

Ahead of what's expected to be a busy Independence Day holiday weekend, Newsom said that he wanted to be "proactive and get us through the 4th of July weekend in a way not to see a spike in cases."

These are big changes: Nearly three-quarters of California's roughly 40 million residents live in these 19 affected counties. And even if you don't live in Contra Costa, Santa Clara or Solano Counties, there are also certain changes ahead of this holiday weekend that may still affect you in the Bay Area.

Read on for how and why your plans might change.

What's this "county monitoring list" I'm hearing about?

These changes to the shelter-in-place restrictions are part of the "dimmer switch" approach Newsom has long promised to use in reopening the state, in which restrictions can be reinstated as well as eased. Where California officials decide to make those changes depends on how each county performs on the state Department of Public Health's monitoring list.

The list records elevated disease transmission, increasing hospitalizations and limited hospital capacity metrics for every county. If a county isn't meeting threshold criteria (i.e. if it's starting to concern the state), you'll see blue numbers on this tracker, because it's joined the "watch list." The 19 counties subject to Newsom's new order were called out because they've been on the watch list for at least three consecutive days.

I live in one of the Bay Area counties listed. What changes for me?

As of Wednesday, July 1, if you live in Contra Costa, Santa Clara or Solano Counties, or any of the other 16 counties on the list, you'll see the following closures — either sustained or newly-imposed — for indoor operations of:

• Movie theaters
• Wineries and tasting rooms
• Family entertainment centers
• Zoos
• Museums
• Card room gambling

...and all bars, whether drinks are served inside or outside.

Remember, this order affects indoor operations, since indoor spaces pose a higher risk of transmitting COVID-19: A restaurant's outdoor operations, for example, won't be closed by these new rules.

Bookmark your county's reopening plans to see what's in store:

• Contra Costa
• Santa Clara
• Solano

What about open spaces and beaches in the Bay Area?

The governor announced that parking lots at many state beaches near highly populated areas will be closed — and in counties with closed local beaches, state beaches will also be closed.

In the Bay Area, parking lots will now be closed for beaches over the weekend in Marin, Monterey, San Francisco, San Mateo, Santa Cruz and Sonoma counties. That's in addition to existing closures of open spaces and trails around the region because of shelter-in-place orders — so if you're planning to head outside this weekend, make sure you check online before you leave.

Why is Newsom so worried about July 4?

In his address, Newsom said family gatherings have contributed to the state's recent increase in transmission — and that it's an understandable impulse to want to get together, especially over a long holiday weekend.

"Patriotism in a COVID-19 environment can be expressed in a little bit different way," Newsom said, asking people to reconsider attending gatherings with those who are not in their immediate household.

Also, holidays mean celebration, and that often means alcohol. The governor said people may start off a gathering with good intentions, wearing face masks, but after a drink or two, might let their guard (as well as their masks) down — and begin to mix in ways that increase the transmission of COVID-19.

Newsom urged Californians to continue adhering to social distancing protocols and wearing face coverings to limit the transmission of the disease. "Wearing a face covering is a sign of toughness, of resolve, of someone who gives a damn," he said.

Why did Newsom mention firework displays?

Newsom recommended that the 19 counties subject to mandatory closures also consider canceling July 4 fireworks displays, to limit large crowds that could increase transmission of the coronavirus.

But if you're in the Bay Area, this hardly represents a change: Even if you feel like you're hearing fireworks in your street most nights, virtually all official firework displays in the Bay Area have already been canceled.

What if a business doesn't obey these new closure orders?

Newsom’s order is a carrot and stick approach, and it comes with some teeth.

The governor acknowledged that in a state of 40 million people, the order will be hard to enforce if people turn their backs on the guidelines. In response, the state has created multi-agency "strike teams" that will go after those who Newsom says are “thumbing their nose” at safety measures. State agencies included are the Department of Alcohol Beverage Control, the Barbers and Cosmetology Board, California Highway Patrol and Cal/OSHA.

"It's more education. I'm not coming out with a fist," Newsom said, who spoke of wanting to recognize the "magnitude" of these modifications.

Mark Ghilarducci, director of California’s Office of Emergency Services (Cal OES) said the strike teams will begin enforcing measures on July 1, with the authority to issue citations for noncompliance. The initial focus will be on the 19 counties on the watch list, he said.

These teams will target noncompliant workplaces — for failing to  protect the public, but also their workers — and will build partnerships with local public health departments and businesses, Ghilarducci said.