There was a shift in reporting. They gave local health departments the okay to test and post results yesterday. So when a local test gets a positive it becomes "presumed"...which is a technical designation of "yes, they have the virus" but can't be counted as official from the CDC until they confirm it.
So over the next few days you are going to be overwhelmed with news reports of presumed cases from all over the country because they haven't been allowed to test and publish. But now they are. That's why the spate of presumed positives today...they've had patients whom they suspected had covid but couldn't confirm or report it.
except that the kits the CDC sent out are faulty!