Phase Diagram (left): The average projection of 250-hPa zonal wind anomalies onto the NPJ phase diagram 3-7 days prior to each extreme event is
identified with a red 'x'. The numbers in the blue boxes identify the number of extreme events that were preceded by a particular jet regime.
Synoptic Maps (right): The composite flow evolution beginning 10 days prior to the initiation of an extreme event and ending 10 days after the initiation of an extreme event.
Variables shown include (1) 250-hPa wind speed, geo. height, and standardized geo. height anomalies, (2) 500-hPa relative vorticity, geo. height, and standardized geo. height anomalies, (3) 700-hPa geo. height, precipitable water, and standardized precipitable water anomalies (4) mean sea level pressure, 1000-500-hPa thickness, and 850-hPa standardized temperature anomalies.