Severe flash flooding risk continues across Central Texas overnight
The overnight hours between Wednesday, June 11 and Thursday, June 12 are set to bring dangerous weather conditions across Central Texas, especially in and around Waco, Austin, Killeen, and San Antonio. The National Weather Service has now escalated the situation by issuing a Moderate Risk alert for excessive rainfall, based on the latest runs of the HRRR (High-Resolution Rapid Refresh) model and live radar data.
Forecast radar and storm evolution
According to the 0Z HRRR run, multiple storm systems are expected to train over the same regions—greatly increasing the risk of flash flooding, particularly in areas with already saturated soils from recent storms. This repeated heavy rainfall will most severely affect the I-35 corridor, the Hill Country, and urban centers like Austin and San Antonio.
Updated forecast timeline for June 11-12 (local time)
7 PM – 10 PM (June 11)
Storms are expected to initiate across the Concho Valley and Edwards Plateau, gradually pushing eastward into Central Texas. Though initially scattered, some cells may carry hail, strong gusts, and torrential rainfall. A brief tornado cannot be ruled out.
10 PM – 1 AM
As storms begin to organize and intensify, they will track into the I-35 corridor, including Waco, Austin, and San Antonio. This is when the training of storms begins, with successive rounds of rain hitting the same spots and increasing flash flood potential.
1 AM – 5 AM (June 12)
The most dangerous period. Models project rainfall rates as high as 1–3 inches per hour (25–75 mm/h), with localized accumulations potentially reaching 5–8 inches (127–203 mm) by morning. Major flash flooding is likely, especially in low-lying areas and urban zones where drainage is limited.
5 AM – 8 AM
The storm system begins to shift southeast toward the coastal plain, but residual flooding will remain a significant threat from Houston down to Victoria. Rainfall rates may remain high in Southeast Texas through the early morning commute.
Main hazards and impacts
The primary threat remains rapid-onset flash flooding, which will be most intense in flood-prone urban areas, low-water crossings, and poorly drained roads. Rainfall totals of 5 to 8 inches (127–203 mm) may quickly overwhelm local infrastructure, and residents are strongly advised to remain alert and prepared for sudden changes in conditions.
With soils already saturated, even moderate rainfall could lead to runoff and flooding, intensifying the overall impact. Power outages, road closures, and emergency rescues are all possible as the night progresses.
Storm monitoring and emergency alerts
Residents from Waco down through San Antonio and into Southeast Texas should ensure they have multiple reliable ways to receive weather alerts overnight, including NOAA Weather Radios, mobile alerts, and emergency broadcast services. Driving through floodwaters is life-threatening—turn around, don’t drown.
Stay connected to trusted weather updates through the overnight hours and into Thursday morning as this significant weather event continues to unfold.
