Jet streams are fast flowing, narrow air currents in the atmosphere. It is the physical mechanism of a teleconnection. The main terrestrial jet streams are located near the altitude of the tropopause
Clouds along a jet stream over Canada.
General configuration of the polar and subtropical jet streams
Hurricane Flossie over Hawaii in 2007. Note the large band of moisture that developed East of Hawaii Island that came from the hurricane.
El Niño–Southern Oscillation is a global climate phenomenon that emerges from variation in winds and sea surface temperatures over the tropical Pacific Ocean. Those variations have an irregular patter
Jet stream
…into two or more parts, combine into one stream, or flow in various directions including opposite to the direction of the remainder of the jet. The El Niño–Southern Oscillation affects the location of the jet streams, which in turn affects the weather over the tropical Pacific Ocean and affects the climate of much of the tropics…
Sea surface temperature anomalies in November 2007, showing La Niña conditions
Between 50,000 and 100,000 people died during the 2011 East Africa drought.