May 4, 2018
The combination of a late-season dry (cold) front associated with an upper level trough provided sufficient lift of moist and unstable air into a slow moving band of thunderstorms in south central Starr County on May 4th. Flash flooding on locally hilly terrain, including arroyos that over topped their banks, impacted Rio Grande City during the mid evening.
Source: NOAA National Weather Service Storm Events Database (event 761525). Narrative written by NWS staff at the time of the event.
This event is one of many recorded floods in Starr County. See the full FEMA flood zone map, NFIP claim totals, and disaster history for the area.