Harris County Judge Lina Hidalgo on Wednesday will unveil the county’s guidance for school reopenings, recommending based on a handful of COVID-19 metrics that schools offer only virtual instruction in the coming weeks until the virus is further curbed.

County officials are issuing the guidance as families and education officials continue to grapple with the idea of resuming in-person classes in the coming weeks, and after Gov. Greg Abbott barred local officials from ordering campus shutdowns to stem the spread of the coronavirus.

Under the non-binding guidance, Hidalgo and county health officials will recommend that school districts offer only virtual instruction as long as Harris County, across a 14-day span, records more than 400 new COVID-19 cases per day, remains above a 5 percent test positivity rate or continues to devote more than 15 percent of hospital beds to COVID-19 patients.

School districts are advised to reopen with reduced capacity as those metrics improve and Harris County hospitals see a 14-day average decrease in their general and intensive care unit bed populations. At that point, school officials can consult with Harris County Public Health officials on their plans to reopen.

Harris County officials are recommending schools remain closed longer than some other organizations.

Researchers at Harvard’s Global Health Institute recommended that schools could begin to partially reopen once daily case counts total about 25 per 100,000 residents — a metric that El Paso’s health authority, Hector Ocaranza, followed in issuing his campus reopening guidelines.

Harris County’s metric recommends starting to reopen only once daily case counts reach about 8.5 per 100,000 residents.

Hidalgo and county health officials are set to roll out the guidance, which they are billing as a “roadmap to reopening schools,” at a 2 p.m. news conference. The metrics will be presented using the county’s existing COVID-19 “threat level system” — a color-coded mechanism the county is using to advise residents on the severity of the pandemic — and are based in part on models used in other states and countries, according to a draft of the roadmap.

Harris County has remained at the worst threat level since late June. Across the last 14 days, the county has averaged 529 cases per day outside Houston and more than 1,400 overall, while COVID-19 patients through Tuesday made up 32 percent of intensive care unit beds across the county. Just 13 percent of general beds are being used by COVID-19 patients, though the county guidance recommends that both general and ICU bed usage fall below the 15 percent mark.

County officials have not yet publicly released the rate of COVID-19 tests coming back positive, though the Houston Health Department and Texas Medical Center on Monday reported positivity rates of 14.6 percent and 10.6 percent, respectively. The city’s 14-day average has continued to decline since peaking at nearly 30 percent in early July, but remains above the county roadmap’s 5 percent threshold.

Hidalgo and Umair Shah, the director of Harris County’s public health department, lack the authority to order compliance with the roadmap before the school year begins. Abbott said July 31 that local school boards and state education officials can limit the reopening of buildings in the first eight weeks of the school year, but county officials may not shut down campuses preemptively.

The governor said local health authorities may shut down campuses in response to confirmed outbreaks in a building, but Texas Education Agency leaders said public school districts risk losing state funding if schools remain closed for longer than five days.

Once conditions improve, the county roadmap advises that school districts can reopen at 25 percent capacity or 500 students, whichever is lower. They can increase to 50 percent or 1,000 students when the county reaches even lower levels, before returning to regular in-person levels at the fourth and final level.

The roadmap states that the county must see a decrease in all four metrics — daily cases, positivity rate, hospital usage rate and hospital population — before moving to the next reopening phase.

“If any one of these indicators is not at a satisfactory level, our ability to manage the virus’s impact on our community is diminished,” the roadmap states. “For example, if disease transmission indicators are at lower levels but our COVID-19 hospital population is high, we must continue to maintain preventative measures to ensure that reopening schools does not overwhelm the healthcare system.”

The roadmap also encourages superintendents, upon reopening, to prioritize in-person learning for students with disabilities or “significant academic gaps,” those experiencing homelessness, or those in state-run protective daycare or who live in low-income households without reliable internet, among other groups.

Nearly all Harris County school districts are scheduled to remain closed or employ online-only classes through at least Labor Day. However, a few outliers remain on track to welcome back some students in the next few weeks.

Humble ISD is scheduled to begin limited in-person classes on Monday, allowing students receiving special education services to return. The district will allow all elementary school students to resume face-to-face instruction on Aug. 24, while middle and high school students will return for part of the week and continue online classes for the remaining time.

Humble ISD Superintendent Elizabeth Fagen has noted that the district’s corner of northeast Harris County is reporting fewer confirmed cases than other local areas. County officials alluded to this argument in the reopening roadmap, writing that “hotspots anywhere in Harris County impact our ability to manage the virus’s impact everywhere.”

Clear Creek ISD will host in-person classes beginning Aug. 31 for about 10,000 of its 42,000-plus students. The rest of the district will resume face-to-face classes on Sept. 14.

All public school families can choose to remain in virtual-only classes indefinitely. Districts can require staff members to return to work in-person, though employees can receive accommodations through the Americans with Disabilities Act and other workplace laws.