The snow forecast for D.C. was shrinking Monday afternoon, and Mayor Muriel E. Bowser was growing less concerned about its potential impact when her senior adviser received an unexpected call: President Trump wanted a briefing from Bowser on storm preparations.

To say the request came as a surprise at City Hall, two blocks from the White House, would be an understatement.

Presidents have over the years invited D.C. mayors to ceremonial and political events, but no one could recall a D.C. mayor being summoned to the Oval Office to brief the president — not for Nor’easters that paralyzed the city; not when a 2011 earthquake damaged city landmarks; not even after the attacks of Sept. 11, 2001.

“I don’t think I’ve ever heard of such a thing,” said D.C. Council member Jack Evans (D), who has represented Ward 2 since 1991.

The Oval Office discussion — about a storm that ultimately dropped just 2.5 inches of snow on the White House lawn — remained the source of intense debate Tuesday among city leaders.

Did the leader of the free world really need a storm briefing from the D.C. mayor? Was it a genuine attempt to coordinate with District officials? Or was it a condescending swipe at the city, raising doubts about whether it was prepared to handle snow?

“It may be benign, but it certainly has the impression of ‘Who’s in charge here?’ and ‘We’d like you to inform us of what you’re doing because we’re superior to you,’ ” said D.C. Council member Mary M. Cheh (D-Ward 3), whose committee oversees snow removal.

There is no official record of the meeting. White House pool reporters were not informed, and no transcript was released. The event was announced 20 minutes after it ended, in a pair of tweets from Trump:

“Meeting w/ Washington, D.C. @MayorBowser and Metro GM Paul Wiedefeld about incoming winter storm preparations here in D.C. Everyone be safe!”

Reached by telephone Tuesday as they traveled the city inspecting road conditions, Bowser and her aides filled in some gaps, and said they are pleased that the White House reached out.

The request for the presidential briefing was made about 4 p.m., aides said, and seemed hastily arranged. The invitation came about 45 minutes after Politico posted an article on its website with the headline: “Will Trump bungle first big snow threat like Obama did?”

Bowser was told that she needed to be at the White House at 6 p.m., and that she could bring one guest.

She chose Paul J. Wiedefeld, the general manager of Metro, hoping for an opportunity to remind the White House of the importance of the D.C. area transit system, which says it needs a major federal investment.

When Bowser sat down opposite Trump in the Oval Office, she said, she got the impression that Trump and his aides were earnestly trying to get their bearings ahead of the storm.

(Jayne Orenstein,Whitney Leaming,Whitney Shefte,Lee Powell,McKenna Ewen/The Washington Post)

“It was a new administration that was dealing with its first storm of the East Coast and its first decision around federal workers,” she said. “His intent was making sure that all of the players knew each other and we have the right contacts and that if there were things the [federal] government could be doing, that they were being done.”

Bowser, whose mostly Democratic constituents overwhelmingly oppose Trump, has been carefully modulating her posture toward the new administration, mindful that the White House and Congress hold unusual sway over her city.

She has lobbed indirect criticism of Trump’s policies, including his approach to illegal immigration, by pledging to use city funds to help immigrants fight deportation and Tweeting “Our values didn’t change on Election Day but some of them have come under attack.” She attended Trump’s inauguration, but also the massive women’s march the following day that was billed as a protest of his election. Bowser, who Tweeted a steady stream of messages about the snow to her 34,000 followers, did not include anything about her visit to the Oval Office.

The mayor said she told the president that his team had been attentive, noting that she had received a call earlier in the day from the regional coordinator for the Federal Emergency Management Agency. Trump’s homeland security adviser, Thomas Bossert, also attended the Oval Office meeting.

Bowser said she thought Wiedefeld did a good job of stating the importance of the Metro system, which transports more than 40 percent of the federal workforce in the region.

“That introduced another part, which they might not have recognized was so integral,” she said. “And for the president, it put a face to Metro.”

Evans, who is also the Metro board chairman, said that he spoke with Bowser and Wiedefeld after the Oval Office briefing and that he thought the impromptu meeting was “terrific.”

“I said to Paul, ‘You got in front of the president on Metro. How did that happen?’ ” Evans said.

It wasn’t the first interaction between Metro officials and the Trump team. A controversy erupted last year when Trump’s image was not included on a special SmarTrip card issued for the inauguration. Metro said at the time that Trump’s transition team did not respond to its request for permission to use a photo. Eventually a compromise was reached: Metro offered commemorative sleeves that featured a photograph of the president and the text “Make America Great Again!”

Another point of contention came in January when White House spokesman Sean Spicer gave out false Metro ridership numbers as the White House incorrectly claimed that record crowds had attended the inauguration. Spicer later said the inaugural committee had provided incorrect information.

Metro operated on a weekend schedule Tuesday morning, with minimal reports of delays, while Bowser kept city government and schools open on a two-hour delay.

Evans said he thought the experience of D.C. and Metro would provide a new base to discuss Metro funding with the executive branch.

“It’s terrific, now when we circle back with the White House, they’ll see we’re competent and we can do a good job running things.”