Recent case numbers, including the 3669 new infections reported on Thursday, have been factored in to project when infections will peak and what that number may be.
Premier Steven Marshall will release the information on Friday, but has already indicated the high point is likely to come in the third or fourth week of January.
"This is going to be short and sharp. I don't think this is going to be something that lingers right throughout this entire year," he said.
"We are coming up to the peak in South Australia."
Officials will also provide more details on Friday on the arrangements for schools in the first term.
Some students will head back to the classroom on schedule, with others to learn online for at least two weeks.
Under the new arrangements, schools will open as planned on January 31 for children of essential workers and for students considered vulnerable.
Other students in reception, years 1, 7, 8 and 12 will return on February 2, with other years resuming face-to-face learning from February 14.
Students facing the longer delay will learn online for the first two weeks of term one.
Mr Marshall said a range of options was considered but the strong advice from education officials supported the "hybrid" model.
"We know there was always going to be disruptions for the start of term one," the premier said on Thursday.
"We want to get as many people into the classroom as possible but we've also got to be mindful of making sure it's safe for students, for our staff and, more broadly, the entire state," he said.
"The reality is there were no easy solutions. There was no simple, clear-cut way of doing this."
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