Weather San Antonio: Severe Thunderstorm Alert—Hourly Forecast & Safety Tips

SAN ANTONIO – A volatile weather pattern is taking hold of South-Central Texas, and the latest forecast shows the Alamo City bracing for several rounds of strong to severe thunderstorms before a cooler, drier weekend. Severe storms late Monday Meteorologists with KSAT’s Weather Authority say an outflow boundary sliding south from the Hill Country will ignite storms after 7 p.m. Monday, lasting through about 2 a.m. Tuesday. The National Weather Service has issued a Tornado Watch for Bexar and surrounding counties, with the greatest threats being tennis-ball-size hail, 60–70 mph wind gusts and pockets of flash flooding. Key timing • 7 p.m.–2 a.m.: Highest chance for hail and damaging winds • 10 p.m.–1 a.m.: Isolated tornado possible, especially northwest of Loop 1604 • After 2 a.m.: Storms weaken and drift south Rain-soaked Tuesday & Wednesday Remnant boundaries linger Tuesday, keeping rain chances near 40 %. Daytime highs fall to the upper 80s to near 90 °F, but abundant humidity will push the heat index into the mid-90s. Scattered thunderstorms redevelop Wednesday afternoon as a weak frontal boundary stalls over the I-35 corridor. 10-Day snapshot According to The Weather Channel’s extended outlook, temperatures moderate mid-week before climbing again by Sunday: • Mon: 94 / 73 °F – storms late • Tue: 90 / 74 °F – scattered storms • Wed: 85 / 73 °F – scattered storms • Thu: 89 / 74 °F – heavy PM thunderstorm risk • Fri: 85 / 70 °F – mostly cloudy • Sat: 87 / 72 °F – partly cloudy • Sun: 91 / 73 °F – stray shower, hotter trend Why the stormy stretch? A slow-moving upper-level trough over West Texas is steering pulses of Gulf moisture into the Rio Grande Plain. Each afternoon, daytime heating and boundary collisions spark storms that drift toward San Antonio. Until the trough lifts northeast late Thursday, daily rain chances hover between 30 % and 50 %. Flood, hail and wind safety tips • Turn around, don’t drown: Just 6 inches of moving water can sweep a vehicle off the road. • Find sturdy shelter: Large hail can shatter windows; move cars into a garage or under a carport. • Enable wireless emergency alerts on your phone for tornado and flash-flood warnings. • Prepare for power outages: Charge devices and keep a flashlight handy. • Secure loose patio furniture that can become windborne debris. Air quality & allergens Storm outflows will temporarily drop ozone levels, but high humidity supports mold spores. If you suffer from allergies, plan to stay indoors whenever rain-cooled winds kick up tree pollen. Looking ahead to Memorial Day weekend By Friday night a ridge of high pressure noses in from northern Mexico, trimming rain odds to 10 % and allowing highs to return to the low 90s. Dew points trend lower, so it will feel noticeably less muggy for Saturday cookouts and Sunday River Walk strolls. Bottom line If you hear thunder this week in San Antonio, odds are strong a severe storm isn’t far away. Keep the rain gear close, monitor local radar, and stay weather-aware until the pattern calms heading into the weekend.