Walmart U.S. Chief Marketing Officer Barbara Messing is stepping down as of Aug. 30 to return to the San Francisco Bay area. Some of her duties will be handled temporarily by former Target and DreamWorks chief marketer Michael Francis, according to an internal memo.

Messing “has decided to leave Walmart and return to the Bay Area with her family,” according to the memo from Walmart Chief Customer Officer Janey Whiteside, to whom Messing has reported and who joined the giant retailer at the same time as Whiteside just over a year ago. Whiteside credited Messing with “memorable and effective creative campaigns that reached our customers in new and unexpected ways.”

Francis, the former Target CMO and DreamWorks chief brand officer and JC Penney president, who has consulted for Walmart since late 2015, “has agreed to join us full time to guide the Retail Marketing team,” Whiteside said. But Walmart is searching for a new chief marketing officer and a new direct report – a senior vice president of Retail Marketing to lead a newly created team under the CMO.

Messing, previously CMO for TripAdvisor, was based at Walmart’s primary U.S. headquarters in Bentonville, Arkansas, while Whiteside, a former American Express marketer, is based at the retailer’s Hoboken, New Jersey, e-commerce offices. Whiteside reports jointly to Walmart U.S. CEO Greg Foran and Walmart U.S. E-Commerce CEO Marc Lore.

The shakeup comes despite strong results for the retailer of late, with last quarter’s U.S. same-store sales up 2.8 percent and e-commerce sales up 37 percent, topping expectations. Walmart has had 20 consecutive quarters of same-store sales growth and outgrown Amazon in U.S. e-commerce -- albeit from a considerably smaller base -- in recent years.

But Walmart's marketing department has seen considerable flux since longtime CMO Stephen Quinn left in late 2015. His successor, Tony Rogers, left to become senior VP and chief member officer of Walmart-owned Sam’s Club last year, making room for Whiteside and Messing to join. The new U.S. CMO will be Walmart’s fourth in four years (or possibly fifth, including interim chief marketer Francis).

Walmart has made a series of marketing appointments in recent months under Messing, including American Express veteran Rich Lehrfeld, who joined in June as senior VP of brand marketing, creative and media.

As part of a new reorganization coinciding with Messing’s departure, Walmart’s marketing operations group will now report to Lehrfeld. “We were able to find some synergies within the organization” with moves in the marketing department, Whiteside said in the memo.

Brittney Duke, who had overseen marketing operations as vice president, is joining the new Retail Marketing team as VP for general merchandise marketing. David Echegoyen, who in June began overseeing marketing for grocery, pickup & delivery, services and digital acceleration, will become part of that team too.

Ciara Anfield, who had been senior director-store experience marketing, is being promoted to VP for consumables marketing. Karissa Price, who had been senior director of health and wellness marketing, is being promoted to VP over the same area. Alvis Washington, VP of store experience marketing, will also join the Retail Marketing team.