After a relatively weak monsoon across the southwestern U.S. in 2019, expectations were high for an active 2020 monsoon season. Unfortunately, the opposite happened and June through September precipitation totals were record low for many stations across the region. The summer was also the hottest on record for many locations. This presentation will provide a basic background of the climatology of the North American Monsoon System with respect to shifts in circulation patterns, moisture sources, and patterns of precipitation.
