South Texas is in for a soaking weekend, with heavy rain and a risk of flash flooding Saturday, Nov. 7, and Sunday, Nov. 8, 2026. A storm system moving in from Mexico is expected to drop 2 to 3 inches across much of the region by Monday, with a few spots topping 5 inches, according to Texas Storm Chasers.
The bigger danger arrives Sunday. Saturday’s rain will soak the ground, so Sunday’s downpours across the Rio Grande Plains, the Rio Grande Valley and the Coastal Bend will have nowhere to go. North Texas, the Panhandle and Houston stay mostly dry.
When will the heaviest rain hit South Texas?
Rain starts tonight out west in the Borderland and Big Bend, then spreads east Saturday. The National Weather Service office in Austin and San Antonio forecasts widespread showers and storms from Saturday through Sunday night. Everything lights up Saturday night, and the focus shifts south through Sunday afternoon and evening.
AccuWeather says the risk may be greatest from near San Antonio and Laredo to Corpus Christi, stretching south to Brownsville, where downpours will be more concentrated.
Why is Sunday more dangerous than Saturday?
Because the ground will already be full. Saturday’s rain saturates the soil, so Sunday’s storms are more likely to run off into streets, low water crossings and creeks. The Weather Prediction Center placed parts of South Central and South Texas under a Slight Risk of excessive rainfall from 6 a.m. Sunday to 6 a.m. Monday…