Time-lapse video by Pete McBride @pedromcbride / Lightning crackles across the sky over the Grand Canyon in Arizona. Though Arizona typically sees less than 10 inches of annual rainfall, during the state's monsoon season—generally mid-June to mid-September—thunderstorms can generate two or three inches in less than a day's time, which then leads to flash floods and water accumulation in low-lying areas. For more from this open-air cathedral, follow @pedromcbride . #grandcanyon #lightning #timelapse #nature