20 July 2016
Here is a radar image showing the nearly circular outflow boundary, from the NWS in Memphis.
Here are the obs from the airport at the time of the event.
Angela Fritz, at Capital Weather Gang, posted an image of an amazing downburst over Phoenix earlier this week here. The damage from these events are often mistaken for tornado damage, and a famous downburst led to the crash of Delta Airlines flight 191 in Dallas, on August 2,1985. This led eventually to a series of terminal doppler weather radars at airports that give warnings of these events, which can be deadly to air travellers.