Sep 9, 2022
Broad southeast flow associated with the circulation of Tropical Storm Kay, which was located just west of the Baja California Peninsula, set up across Arizona. This helped in advecting moisture into the area with PWAT's in excess of 1.5. Instability was also present with MLCAPE values of around 1000 J/KG. In addition, there was upper-level diffluence over south-central Arizona, which helped enhance the shower and thunderstorm activity.
Source: NOAA National Weather Service Storm Events Database (event 1056469). Narrative written by NWS staff at the time of the event.
This event is one of many recorded floods in Maricopa County. See the full FEMA flood zone map, NFIP claim totals, and disaster history for the area.