Bess, 21, played in two Tests against Pakistan last summer after Leach was ruled out of the series with a broken thumb, and proved his aptitude for the big stage with a fifty on debut at Lord's before taking three second-innings wickets at Headingley to help square the series.
However, his chances of staying in contention for this summer's Ashes had been looking bleak after he was overlooked for the early rounds of the County Championship season, with Leach taking six wickets at Trent Bridge in April to help propel Somerset to the top of the table.
Despite the friendliness of his rivalry with Leach, Bess had warned - in an interview with ESPNcricinfo in November - that his ultimate aim at Somerset was to "knock Leach off the No.1 spot".
That now cannot happen in the near future, but with Bess available for selection for Yorkshire's upcoming Championship fixtures against Kent, Hampshire, Essex and Surrey, he has the ideal platform to develop his game on the field instead of in the nets and second XI matches.
"I haven't been getting the cricket that I would like," Bess told Yorkshire's website. "Once I got a general idea of where I was, I asked if I could go on loan. I've been on the loan list for a while and luckily Andrew Gale got in touch through my agent and spoke about an opportunity for a month or so, playing Championship cricket for Yorkshire.
"At the moment it's a chance to get some cricket under my belt. To have this opportunity and for Yorkshire to be able to give me this opportunity, I hope I can repay them."
Martyn Moxon, Yorkshire's Director of Cricket, said that his county's own dearth of experience in the spin department made Bess's signing a no-brainer.
"When Dom became available, we thought that it would be advantageous for us," Moxon said. "It helps the balance of the team as he can bat as well as bowl his off-spin.
"Dom is a highly talented young cricketer who clearly needs to be playing first-team cricket. At Somerset, Dom isn't getting the opportunity with Jack Leach playing, so we feel that it is the right time to loan him.
"Our senior spinner in Josh Poysden hasn't played any red ball cricket yet this season. James Logan is currently injured, and Karl Carver hasn't had much opportunity in red ball cricket so far. Given the circumstances, we felt that it would be a good move for us.
"This is for a month initially. There is an opportunity now for the spinners on the staff to play in the Second XI and hopefully put in some good performances to warrant selection before we assess the situation in a month's time."
Bess is already itching to get started at his adopted home.
"It will be a great experience for me to be put into this Yorkshire side and hopefully I can deliver some good performances," he said.
"I've been on a bit of a journey. But to get out there and play first-class cricket will be brilliant. Whatever side I play for; I want to win. In general, Yorkshire have that attitude, which I love. I want to give both the club and myself the best opportunities."