premise: wind can make air masses to move in the same direction sent2: jet streams may deflect the air masses moved by the prevailing westerlies sent3: prevailing westerlies are prevailing winds from the west toward the east in the middle latitudes between 30 and 60 degrees latitude sent4: united states are located in the middle latitudes between 30 and 60 degrees latitude.
hypothesis: the prevailing westerlies move air masses from west to east accross the united states but may be deflected by the jet streams