7 charts that show how the coronavirus is making a disturbing comeback in Mass.

Coronavirus testing in Dedham last month.Pat Greenhouse/Globe Staff/file

The coronavirus pandemic is making a comeback in Massachusetts.

Citing “disturbing trends” in infections and hospitalizations, Governor Charlie Baker this week announced the latest in a series of steps to combat the deadly virus.

Though the upcoming rollout of vaccines to protect people against the deadly disease offers a glimmer of hope, the initial amounts will be limited, and the winter months ahead are expected to be grim and harrowing, both in Massachusetts and nationally.

These seven charts paint a sobering picture of where we are in the current surge — and offer signs of where we might be heading.

1. The number of cases reported per day

In this first chart, daily case totals reported by the state are shown since the beginning of the pandemic, along with seven-day averages. The chart shows a mountain of cases per day in the spring as a terrified state hunkered down at home, a decrease in cases to a low point around late June, and then a disturbing rise in cases again starting around late September.

In November, case counts started surpassing counts from the spring surge. In December, the increases accelerated. In recent days, the seven-day average has reached more than twice the highest seven-day average of the spring surge.

2. Hospitalizations

Hospitalizations and ICU admissions are on the rise, but the numbers have not yet reached the levels of the spring surge. One reason cited is a higher percentage among the infected of young people, who are less likely to become seriously ill. Still, the state is taking precautions. It has set up one field hospital and another is planned; it has also ordered hospitals to temporarily curtail elective procedures.

“The rate at which Massachusetts residents are getting infected — and the rate at which they are needing medical care — if all continues to move at this pace, is simply not sustainable over time, and our health care system will be put at risk,” Baker warned Tuesday.

3. Deaths

Coronavirus deaths are also on the rise, but they have also not yet reached the spring levels. Doctors have theorized that lower fatality rates may reflect the higher percentage of young people among those infected, improved understanding of how to treat the illness, and less stress on hospital systems.

4. Three different positivity rates that Massachusetts highlights in its daily dashboard

Positivity rates are a closely watched indicator. The lowest line on the chart below is the positivity rate for testing at higher education institutions. In college testing programs, asymptomatic people can be tested repeatedly, which results in a low positivity rate. The line above it shows the rate of positive tests among all tests administered. The top line shows the rate of positive tests when the higher education testing is removed.

The latter two numbers have been marching higher this fall, with a few bumps on the way.

5. A fourth kind of positivity rate

This is the positivity rate among people tested for the first time. The metric is not featured by the state on its daily dashboard, but it can be calculated from data files released by the state. It is climbing.

6. Traces of the virus found in waste water at the Massachusetts Water Resources Authority’s plant on Deer Island

Waste water at the treatment plant is being tested for copies of the virus as part of a pilot project. The hope is to pick up early signals of future rises in infections. Results are broken down into two groups: a northern section, which includes Boston, and a southern section. The levels took off in the fall. The levels recently reached higher levels than those recorded during the spring surge. Company officials estimate the numbers run four to 10 days ahead of case numbers.

7. A model of the future

This chart shows the University of Massachusetts’ weekly ensemble model of where the pandemic could go next for Massachusetts. Researchers at the lab combine numerous models to glean their collective wisdom and project the future several weeks ahead, in this case up to Jan. 2.

The four-week model shows weekly confirmed and probable case counts are expected to keep rising beyond current levels, though the growth is expected to slow somewhat in the fourth week.

The UMass ensemble model case forecastReich Lab/UMass (Custom credit)

Material from prior Globe stories was used in this report.