The state's biggest area of concern is a rise in hospitalizations, particularly in ICU beds. In most regions, ICU beds are about 75% full now, but are projected to reach capacity by mid-December to early January if current trends hold.
"If these trends continue, we're going to have to take much more dramatic, arguably drastic action," Newsom said, including "the potential for a stay-at-home order for those regions in purple."
Gov. Newsom is referring to the 51 of California's 58 counties in the purple tier -- the most restrictive reopening tier that indicates widespread coronavirus transmission.
This is the tipping point.— Gavin Newsom (@GavinNewsom) November 30, 2020
CA has worked hard to prepare for a surge—but we can’t sustain the record high cases we’re seeing.
Current projections show CA will run out of current ICU beds before Christmas Eve.
Please stay safe & stay home as much as you can for next few weeks. pic.twitter.com/5NJYzHokhE
"This is in the absence of making better decisions," Newsom said of projections showing ICU beds reaching capacity. "This is a chart that says if we just sit back and we are bystanders at this moment, and we don't improve upon our existing efforts, this is what we project might occur.
"I want folks to know that we intend to bend this proverbial curve and impact these statistics favorably."
The governor said the seven-day average of new coronavirus cases is now north of 14,000 per day. To put that in perspective, that number was about 9,900 during our last peak.
"I'll remind you that the high case numbers that we've seen in the last week to 10 days have not even begun to impact hospitals yet," added Health and Human Services Secretary Dr. Mark Ghaly. "We know that it takes about two weeks. So a few days ago, when we had a case level of 18,000 plus cases in the state, that has not yet impacted the hospitals, the emergency rooms and the ICU."
There is widespread concern that the state is about to see an even larger surge in cases -- and eventually hospitalizations -- following the Thanksgiving holiday.
"We are really in a different situation with transmission than we've ever faced before," said Dr. Ghaly. "Every activity that a month ago was lower risk, this month it's higher than ever before."
As coronavirus trends worsen, another nine counties were moved into stricter reopening tiers over the weekend.
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Calaveras, Lake, Plumas, San Francisco and San Mateo counties were moved from the red to the purple tier. Modoc County was moved backward two tiers, from orange to purple. Alpine, Inyo and Mariposa counties were moved from orange to red.
That leaves zero counties in California in the least restrictive yellow tier. One county is still orange and six are still red. The remaining 51 counties are in the purple tier.
The state's total number cases since March is nearing 1.2 million, and the death toll has topped 19,000.
The governor also announced Monday a new relief package for small businesses, which includes a three-month sales tax extension for companies that owe less than $1 million in sales tax.
He also added a small glimmer of hope on the horizon: 327,000 doses of Pfizer's COVID-19 vaccine are set to arrive in California in the next couple weeks. This vaccine requires two doses to be effective.