Show Know now The e eWeather Weather Where are the in the United States Are we learning more about them IN THE WINTER there are re usually two over the United States-both States flowing east at high al al- al The lower one passes in the general vicinity of St. St Louis quite often though it ventures up and down from north and south as it iti I crosses a map of the coun- coun try try The higher can often be found in the vicinity of Chicago and it follows a zig-zig zig course across the coun coun- try Pilots are learning to get into both of them to facilitate eastward flight i THE TilE it is isnow j now known move up and down as well as north and south as they flow eastward i Some say they produce tornadoes torn- torn i aloes when they come down and hit the surface In the summer over the USA only one stream is usually present both having i I moved north from their winI winter winter win- win I ter courses and the southern south- south I ern most one which crosses the lower USA in winter is the only one above us in summer and it is much further north |