Tornado watch until 10 p.m. across much of South Texas
As of this afternoon, a Tornado Watch is in effect for San Antonio and surrounding areas until 10:00 p.m.. While conditions currently appear calm, with a mix of sunlight and cloud cover, things are likely to change rapidly as we head into the evening hours.
Outflow boundary triggers instability
A rain-cooled air boundary, left behind by earlier storms, has settled across the region. With sunlight breaking through the clouds, surface heating is intensifying along this boundary. At the same time, a disturbance aloft is moving across West Texas, sparking thunderstorms from San Angelo to north of Edwards County. Although these storms will remain north of San Antonio for a while, they are expected to grow into dangerous supercells.
Dangerous conditions forming with hail and strong winds likely
Thanks to strong daytime heating and cooler temperatures aloft, a highly unstable atmosphere is building. This creates ideal conditions for very large hail to develop, especially across San Angelo, Austin, and extending into the San Antonio region. As the evening progresses, the storm system may organize into clusters, raising the risk of damaging wind gusts into the overnight period.
Storm timeline: What to expect hour by hour
By 7:00 p.m., a few isolated storms could begin popping up along the boundary, though these will be scattered and unpredictable. However, after 7:00 p.m., storms are forecast to push southward steadily, increasing the likelihood of severe thunderstorm warnings. Risks will include large hail, powerful winds, and the possibility of an isolated tornado.
By 8:00 p.m., radar suggests storms could begin reaching the northern San Antonio metro, intensifying as they advance. The worst weather may arrive between 11:00 p.m. and 1:00 a.m., with potential for training storms, which raises concerns over localized flooding due to persistent heavy rainfall in the same locations.
Heavy rain and residual storms through Tuesday morning
The severe threat should diminish late overnight as storms move closer to the Gulf Coast, but pockets of rain and thunderstorms could still linger across San Antonio into daybreak Tuesday. Areas that receive repeated storms could see significant rainfall totals by Tuesday morning, especially in low-lying or flood-prone zones.
Stay tuned to local alerts and updates as conditions evolve this evening.
