Your wallet could get a shock tonight along with the sky: the northern lights tonight are forecast to dip unusually far south, but experts warn that chasing the aurora could trigger a surge in gas prices and hotel rates in your area. As solar activity peaks on this rare viewing event, travel costs spike 40% in northern states, adding up to $120 for a spontaneous road trip. Meanwhile, cell service providers admit they're throttling data speeds near popular viewing spots, risking extra fees if you try to stream the show. Save cash by checking local power grids too—a geomagnetic storm this strong may hike your electricity bill later. Don't let the aurora burn a hole in your pocket.