Interesting. Today Sunday Santa Clara County is off the watch list,
not having been on for more than a week. School hasn't started yet.
So are schools still barred for opening unless the watchlist is avoided for 15 days straight? There seems to be a hysteresis problem in these determinations. 3 days presence is not really long enough of a requirement to avoid instability.

In Mountain View, two of the 3 public school districts have announced they will not re-open this year for general "in-person" learning. Any school that does re-open will become a lab for coronavirus spread. Signs should be posted near the schools warning "SCHOOL OPEN FOR VIRUS SPREADING." Sure, infected students and staff and parents will spread the virus to others. But it will be less of a disaster than opening all schools at once.

To close the schools is a huge mistake! Children rarely get coronavirus or infect adults. In Germany, where children went back to school, it has been demonstrated in large numbers that the children didn't get sick or spread the virus. All other European countries will be opening the schools in fall.
Unfortunately, I don't believe these decisions in California are made because of safety measures but of political reasons with huge detrimental results for the students, parents, and economy. The poorer the family, the greater the damage, many children and families do not have the technical or educational means to help their children at home. Does the county public health officials care?

@Carmen. Give us a link to Germany - other than Trump's grandfather - so we can read what, if anything, you are posting about.