In January, D.C. Mayor Muriel E. Bowser (D) discusses the findings from the final independent auditor’s examination regarding District-wide policies on attendance and graduation outcomes. (Jahi Chikwendiu/The Washington Post)

Fewer than half of the seniors in the District’s traditional public school system are on track to receive their diplomas in June, a drastic shift for a school district that celebrated a record high graduation rate last year.

Data released Friday by D.C. Public Schools show that 46 percent of the 3,623 seniors are on course to walk across the graduation stage, while 21 percent are considered “moderately off track,” meaning they could still earn enough credits for a diploma.

The graduation rate in 2017 was 73 percent, and these latest numbers suggest the city could be bracing for a double-digit dip.

City officials had said they expected the graduation rate to drop this spring following an investigation that undermined the validity of diplomas awarded to the Class of 2017.

The city-commissioned probe determined that 1 in 3 graduates in 2017 received their diplomas despite missing too many classes or improperly taking makeup classes.

The graduation rate reflects the percentage of students who started high school in fall 2014 and are set to receive their diplomas in four years. Twenty percent of students who started their freshman year with the Class of 2018 have withdrawn or transferred, and the city needs to determine how many of these students dropped out and how many transferred.

After the investigation into the 2017 graduation rate, the school system promised to stringently enforce long-ignored attendance policies, which say that students should fail a class if they are absent more than 30 times in a school year.

The probe portrayed a culture in which teachers felt pressured to award diplomas even if teens failed to meet requirements, all in the name of improving graduation rates.

This is the first year the city has released graduation projections months before diplomas are awarded, and city officials said they are trying to be transparent.

The city released a first batch of data in February, which showed that 42 percent of seniors attending traditional public schools were on track to graduate, while 19 percent were considered “moderately off track.”

Students who are on track to graduate have passed or are passing all courses required to graduate. Those who are moderately off track are failing at least one required course but can still earn the credits through credit recovery or summer school.

The data released Friday offers a slightly more sanguine projection for graduation than the figures presented in February.

The April data indicates that among comprehensive high schools, Anacostia has the lowest percentage of students on track to graduate. Of the school’s 175 seniors, only 25 percent are on track to graduate, and 26 percent are “moderately off track.”

At Ballou High — the school at the epicenter of the graduation scandal — 33 percent of seniors are on track to graduate, and 34 percent are moderately off track. At Wilson High, considered the city’s most sought-after comprehensive school, 62 percent of seniors are on track to graduate.

The District’s magnet and application schools have the highest expected graduation rates. At Banneker, 85 percent of students are passing or have passed all courses required for graduation.

The last day of school for D.C. students is June 15.