The Circumglobal North American Wave Pattern and Its Relation to North American Cold Events

The anomalously cold Eastern US winters alongside drought conditions in California which occurred during past winters, have been associated with strong undulations in the tropospheric jet stream which bring cold polar air southward over the Eastern part of the continent, and warm dry conditions over the south west. We propose that these jet undulations are associated with the North American part of the Circumglobal Teleconnection Pattern (CTP) - a pair of zonally oriented waves of zonal wavenumber 5 which are in zonal quadrature with each other. While the PNA is associated with the first circumglobal wave pattern, Eastern North American extreme cold events are associated with the second pattern. The implications for the physical drivers of such cold events, and possible predictability via Asian wavepacket precursors will be discussed.