By Katie Nielsen

SAN JOSE (KPIX) — From Wednesday to Thursday, California has seen a 2-day state record of COVID-19 deaths: 1,042.

ICU capacity in the Bay Area was down to 3.5% on Thursday. Public health officials said they could predict the drop because they’ve now discovered that coronavirus infections follow a timeline.

As of Thursday, there were only 3 ICU beds available in all of Santa Clara County. One public health expert says that, to understand why, we need to look back to Thanksgiving.

“Thanksgiving has had a profound effect and we’re still seeing the residue of that right now,” said Dr. John Swartzberg, a public health professor at UC Berkeley. He says experts figured out these COVID surges actually follow a predictable timeline.

After a holiday gathering where people have been exposed, Swartzberg says it takes about six days for them to become symptomatic and get tested. That sends the positive test rate up.

Within a week, about 20% of people who get infected with coronavirus need to go to the hospital so hospitalization rates go up.

A few days after that, some will need more advanced medical care and ICU admissions increase.

Another week after that, death rates start rising, leading us to where we are now, exactly six weeks after Thanksgiving, seeing a record number of people dying from COVID-19.

“We can actually see the future with this virus now. It’s predictable and it’s terribly concerning,” Dr. Swartzberg said.

Christmas was two weeks ago and New Year one week ago. Health experts say that, in the coming days and weeks, the numbers will tell us how successful people were at keeping their distance during the holidays.