Sep 4, 2020
The airmass over South Central Texas was very moist with high precipitable water. A weakness developed in the ridge in the mid-levels of the atmosphere above this moist boundary layer. This allowed thunderstorms to develop and some of these storms produced heavy rain that led to flash flooding.
Source: NOAA National Weather Service Storm Events Database (event 920677). Narrative written by NWS staff at the time of the event.
This event is one of many recorded floods in Hays County. See the full FEMA flood zone map, NFIP claim totals, and disaster history for the area.