AllNature

Global mountain torque just smashed the old record in my CORe analysis going back to 1968, exceeding it by a full standard deviation! East Asia and the Andes supplied most of the positive torque, transferring angular momentum from the solid Earth to the atmosphere as the AAM tendency carried the GWO trace off the right edge of the phase diagram. Twin upper-level anticyclones over the eastern tropical Pacific are consistent with persistent El Niño heating, while strong Pacific westerlies in both hemispheres help guide vigorous downstream Rossby wave dispersion. Synoptic dynamics appear to be driving the next round of ridge growth. Around Nov. 19–21, ECMWF and its ensembles predict higher-θ air extending poleward along the dynamic tropopause on the eastern flank of a Pacific trough as the ridge amplifies over western Canada. Some guidance extends the ridge into Alaska. An active Pacific storm track could continue beneath the ridge, and the reach/intensity of any cold surge will depend on the downstream trough and the quality of the cold air it can tap. If the stratospheric disturbance couples more strongly to the troposphere, it could favor more persistent high-latitude ridging later in November and into December.