MAMMOTH LAKES, Calif. (AP) — A spring storm dumped more than than 3.5 feet (1 meter) of snow in California’s eastern Sierra Nevada, briefly closing a key interstate and extending the ski season at Mammoth Mountain. The weekend storm came just weeks after a March heat wave melted much of California’s snow, forcing many ski resorts to close. More snow was possible Monday. On April 1, the Sierra snowpack , which provides one-third of California’s water, stood at just 18% of average, a reading in