Bill Newhall of Baltimore glanced at our weather map recently and was startled to find TWO jet streams. "For real? Are there two jet streams?" he asked. One Santa, Bill, but two jet streams that affect the continental U.S. The "polar jet" meanders between 30 and 70 degrees north latitude, the "subtropical jet" between 20 and 50 degrees north latitude. Winds in these jets, 6 to 9 miles high, blow between 35 mph and 250 mph. They form between warm and cold air masses, and steer and energize storms.