“Are you ready for 23 feet of water flooding the Eastern Seaboard?” demands 13-year-old Lauduree (Perla Haney-Jardine) in a burst of self-righteous pique late in Future Weather. It’s part of writer/director Jenny Deller’s modest achievement that she understands her protagonist’s obsession with global warming as a logical response to her bleak personal situation. Abandoned by her single mother, living in a trailer park in rural Illinois, Lauduree equates a frustration with her perceived lack of future with the impending doom of the entire planet. The film is most successful as a character study of a stubborn, prickly girl whose intelligence far outweighs her immediate prospects—and, to a lesser degree, of her equally sharp-edged grandmother (Amy Madigan) with whom she goes to live. As a portrait of a semi-hellish backwater, it’s content to give us a glimpse or two of rural desperation and leave it at that—although a school project in which Lauduree and a classmate interview locals about their favorite animal proves an unfortunate lapse of directoral judgment. Similarly, Deller’s pacing remains uneven, taking too long to build to a too-rapid finale, but that at least gives her opportunity to focus on the film’s main asset, devoting ample time to observing its tetchy, sharply drawn lead.