You can reliably forecast most of the beats in BlayneÖ Weaver’sÖ breezy romantic comedy “Weather Girl,” but that doesn’t diminish the small pleasures the movie delivers.

Sitcom vet Tricia O’KelleyÖ brings an appealing brittleness to Sylvia, the “sassy weather girl” (a promotional reference much loathed by Sylvia) on a Seattle morning talk show. Sylvia loses her job after finding out that boyfriend Dale, the show’s preening co-host (Mark HarmonÖ), has been cheating on her. Sylvia’s on-air rant makes her a minor celebrity but torpedoes her career.

The 35-year-old Sylvia soon takes up with her little bro’s best friend, ByronÖ (Patrick J. Adams), promising each other that they’re in it for the sex—no obligations, no complications. Since Because the movie’s genre is all about the complications, we know the deal will be upended.

Writer-director Weaver toys with the older-woman/younger-guy dynamic, but Sylvia’s character isn’t realized enough for it to stick. “Weather Girl” coasts on the charms of its ensemble, which includes brief, funny turns from Jane Lynch and Jon Cryer. Harmon’s a standout, turning his “walking haircut” into a sad sack who’s rendered clueless by too many years of forced banter.