Flash Flood — Llano, Texas

2025-07-04 · near Castell, Llano, Texas

Event narrative

Multiple rounds of thunderstorms produced 7 to 20 inches of rain over the Llano River watershed in Mason County sending a flood wave downstream into Llano County where 2-9 inches of rain fell. There was flash flooding around Castell where the Llano River overtopped the FM 2768 bridge.

Wider weather episode

Tropical Storm Barry moved into and dissipated over eastern Mexico. Moist air from the remnants of Barry moved northward into Texas. Precipitable water values over South-Central Texas increased to near record levels. A mid-level anticyclonic circulation developed and moved over Central Texas providing lift to generate thunderstorms. During the overnight period of July 3-4, a low-level jet streak set up over South Texas and led to training of thunderstorms over the Texas Hill Country. The combination of weather features generated efficient rain making storms that produced 2-3 inches of rain per hour for several hours over the headwaters of the Guadalupe River. Rainfall totals in the area were up to 11 inches which led to catastrophic and deadly flooding along the Guadalupe River in Kerr County. Heavy rain eventually moved eastward causing additional flooding. Flood water killed 117 people in Kerr County and caused an estimated $200 million in damage to public property and infrastructure. There was no estimate for private property damage. Kerr County officials estimated 2,000 structures were damaged or destroyed.

View location on OpenStreetMap → (30.7000, -98.9600)

Source: NOAA Storm Events Database, event_id 1287689. Narrative written by the NWS forecast office that issued the report.