OAKLAND >> Loren Taylor and Barbara Lee are locked in a tight race to be the next mayor of Oakland, a special election that has politically divided the city — including on clear geographic lines — and which may not be decided for weeks.

Taylor, a former city councilmember, held a 51% to 48% ranked-choice lead on election night over Lee, the former East Bay congresswoman — about a 1,100-vote margin.

Alameda County election officials tallied 49,000 votes Tuesday night, and Wednesday they estimated that about 42,000 additional ballots still need to be counted. An unknown number of ballots mailed by election day have not yet arrived.

The next set of results are expected to be released Friday, and further vote counts will be announced every Friday after that. That may sound like a long wait, but Alameda County’s top election official said fewer result drops actually help his team count faster.

Stopping the count — pausing the vote-processing machines — to post results online more frequently would disrupt an extensive tallying process, said Tim Dupuis, county registrar of voters, in an interview.

“Imagine me putting 42,000 envelopes in front of you and telling you to slice each of them open and pull out what’s inside,” Dupuis said Wednesday, attempting to demonstrate the scale of work ahead for his office.

It could be at least a couple weeks before the race is decided. Dupuis has a full 30 days after April 15 to certify the election, but he said Oakland city officials can request for it to happen earlier if the outcomes are no longer in question.

The first returns Tuesday night gave Taylor some more breathing room, but Lee’s voters had narrowed the gap by night’s end.

For many voters, the trajectory might feel like “deja vu,” as Noah Finneburgh, a former campaign consultant for ex-Mayor Sheng Thao, put it on election night. Thao overcame an early deficit to Taylor in the 2022 race, surging past him in later returns to win.

It is harder to predict any clear trend, however, from the results available this time around. The second batch of about 4,200 votes, which favored Lee, exclusively represented ballots cast in person at polling places on election day.

The first batch, which gave the edge to Taylor, were entirely ballots submitted by mail. Ballots cast at polling places are fully tallied, meaning every new set of results going forward will be either mailed votes or those dropped into ballot boxes. In other words, there’s no definitive understanding of whether ballots mailed later will side with either Lee or Taylor.

Across the first 49,000 votes, Lee is leading in precincts across the West Oakland, the city’s downtown and the large swath of town east of Lake Merritt — all the way to the flatlands near the San Leandro border.