Illinois has reached its peak — but that high level in coronavirus deaths could last “a couple of weeks” and see as many as 150 Illinoisans dying of COVID-19 a day.

The COVID-19 projection and worst-case fatality scenario are from scientific modeling released exclusively to the Chicago Sun-Times by Gov. J.B. Pritzker’s administration.

The Democratic governor has been repeatedly asked what models he’s using to make major decisions that are keeping Illinois residents at home, businesses closed and streets and parks largely empty.

That stay-at-home order is expected to be extended.

And Pritzker plans to present graphs and data — alongside some of his researchers — at his daily briefing on Thursday.

So far, 1,565 have died in Illinois.

As horrible as that is, Pritzker plans to show one graph projecting that if the state had not enacted the stay-at-home order on March 21 the death toll would have been 14 times that.

Cameron Mock, chief of staff to the Governor’s Office of Management & Budget, has been reassigned to oversee the state’s projections.

Now his work includes daily phone calls with researchers from the Illinois Department of Public Health, as well as researchers from Northwestern University, the University of Chicago and the University of Illinois at Urbana-Champaign.

The state’s projections are a combination of opinions and research from those three institutions.

Mock and Pritzker’s chief of staff Anne Caprara brief the governor weekly.

And based on the projections, the peak “should be somewhere starting now through the first week of May,” Mock told the Sun-Times.

“I think it’s tough to say, but I think a couple of weeks,” Mock said of the range.

According to a projection obtained by the Sun-Times, the top of the peak could see 150 deaths a day. But during that peak period, the daily range of fatalities could fluctuate anywhere from 50 to 150.

The state saw two days with 125 deaths last week, the highest daily fatalities so far.

Another graph Pritzker plans to show will estimate that the death rate would go up ten times if the stay at home order was lifted Friday – a little less than a week before the scheduled April 30 expiration.

The model shows deaths in the state slowly flattening into August.

Mock admits to being “a little nervous providing that median line,” of deaths from the virus, worrying about public reaction.

“But nonetheless you’ll see that going forward and what you’ll see is, again, a peak in late April, early May and then you’ll see a slow rate of decline, going out into August,” he said.

Mock said ventilator usage is being used “as a sense of how the virus is manifesting itself and it ultimately drives hospitalizations and deaths, unfortunately.”

Pritzker has been coy about the state’s projections. At a Washington Post Live event on Tuesday, he said the peak might hit in mid-May. But Caprara said the administration has been very careful about its data.

“In a traditional fashion a model takes a long to build upon. We’re talking months,” Caprara said. “So we had to take the traditional timeline and speed it up pretty significantly . And number two, models grow smart over time.”

Caprara said as each month goes on, the model “gets smarter and more predictive.”

Caprara said the most important tool the model is showing is infection rates, deaths and hospitalization numbers.

“We’re trying to get to that 14-day period where all of those are declining,” Caprara said. She also warned the state won’t decisively know when it has hit its peak until it begins its decline.

Mock said when Pritzker says the bend is starting to “curve” or flatten,” it signifies “the rate of growth and not absolutely numbers going down.”

Mock said the tail of the death rate is crucial, not just the peak.

“I know a lot of people are going to want to focus on this specific date of what they’ll determine peak to be and some folks out there are going to want to say on the day after, the next day after, we open up the economy,” Mock said.

“What I would focus on is what the tail of that curve looks like and what it’s going to show us is a very slow process out of this, and if you make massive knee-jerk reaction changes, you have a great risk of completely falling back on all the progress that you’ve made thus far.”

And despite President Donald Trump’s applauding other states’ for their quicker re-openings, Caprara said Illinois’ decisions are not political and are “driven by data.”

“Whatever political conversation there is about whether or not we should open or not open, I will say this: none of this should be a political conversation,” Caprara said.

“The reality is, there’s no Democrat that wants to keep the economy closed. There’s no politician who wants to have the state or the country go through a pandemic. The decisions have to be scientific. They have to be medical and they have to be driven by data. And that’s just the reality.”