Most of South Texas is under a Flood Watch from Saturday afternoon, November 7, through Monday morning, as a slow-moving storm system drawing moisture from both the Pacific and the Gulf settles over the region for the weekend. The National Weather Service office in Corpus Christi issued the watch after forecast guidance converged on two to four inches of rain across most of South Texas by Monday morning, with localized totals above five inches — and the Weather Prediction Center has placed south-central and South Texas under a Slight Risk of excessive rainfall, level 2 of 4, for Sunday, the day the heaviest rain is expected.
Source: National Weather Service Corpus Christi, Area Forecast Discussion, 12:24 a.m. CST, Nov. 7, 2026
The watch covers the Coastal Bend, the Rio Grande Plains and the southern Rio Grande Valley. In its excessive rainfall discussion issued at 2:36 a.m. Eastern on Saturday, the Weather Prediction Center in College Park, Maryland, said prevailing southeast flow from the surface up to about 850 millibars will send precipitable water values surging to between 1.5 and 2.1 inches — a deep plume of tropical moisture sitting over southern Texas, mainly south of Corpus Christi and across the southern Rio Grande Valley to the Gulf Coast.
Source: NWS Weather Prediction Center, Excessive Rainfall Discussion, 2:36 a.m. EST, Nov. 7, 2026
Where the heaviest rain is expected to fall
The centre's forecasters said the setup will stay in place for at least 24 hours, with a broad area of moderate to heavy rainfall and embedded thunderstorms across southern Texas and the core of the rain along and south of Interstate 10. The corridor of heaviest rain runs between the Hill Country and the central Rio Grande Valley down to the southern tip of Texas near Brownsville, and the greatest probabilities sit between Laredo and Corpus Christi, with emphasis on Webb, Duval and Zapata counties, the discussion said.
Source: NWS Weather Prediction Center, Excessive Rainfall Discussion, 2:36 a.m. EST, Nov. 7, 2026
The broad forecast is for two to three inches across the region, the Weather Prediction Center said, but the computer models it reviewed were, in its words, quite bullish on locally heavy totals of four to six inches. One run of the European model even produced more than eight inches east of Laredo — a figure the centre flagged as the upper threshold of the potential rather than the expected outcome. The Corpus Christi forecast office, using the same guidance, put it this way: two to four inches through Monday morning, localized totals above five inches, and some guidance as high as nine inches at the extreme end.
Source: National Weather Service Corpus Christi, Area Forecast Discussion, 12:24 a.m. CST, Nov. 7, 2026
FOX Weather's Forecast Center described the same system as a steady, soaking rain rather than sudden torrential downpours, because there is very little atmospheric instability over the region. Its outlook has heavy rain beginning Saturday afternoon from Austin south to Brownsville, with the flash flood risk increasing and shifting south on Sunday — a broad level 2 threat covering parts of the Hill Country and South Texas, including San Antonio — and the most persistent, heaviest rain from Sunday afternoon through Sunday night. Rain lingers over the region into early next week, FOX Weather said.
Why forecasters worry about this ground
South Texas and the Hill Country drain through low-water crossings, dry creeks and rivers that can rise quickly when storms train — passing repeatedly over the same ground. The Corpus Christi office noted that flash flood guidance for the area is comparatively high, at three to five inches of rain in six hours, but warned that if storms start training or moving slowly over the same areas — especially over urban Laredo and along the Coastal Bend — flash flooding may become a concern even below those numbers. The Hill Country's vulnerability is written in recent history: the July 4, 2025 floods killed 135 people when the Guadalupe River rose to record heights, a disaster FOX Weather cited in explaining why forecasters treat this terrain with caution.
The bullseye for this rain — between Laredo and Corpus Christi — sits across some of the busiest freight ground in America: Interstate 35 from San Antonio to Laredo, the main truck route to Mexico; Interstate 37 to Corpus Christi; Interstate 10; and US-83 through the Rio Grande Valley. Space City Weather put the heaviest rain near and south of San Antonio toward Victoria, Laredo and Corpus Christi, with Houston mostly north of the worst of it. Drivers dispatched across Webb, Duval and Zapata counties on Sunday should check Texas road conditions before leaving, expect ponding on low stretches and frontage roads, and never drive through water covering a road or a low-water crossing — the depth and the state of the pavement underneath cannot be judged from the cab.
The coast is in the same system
The same weather brings hazards on the water. The Corpus Christi office flagged a high rip current risk on Sunday along with Small Craft Advisory conditions on the bays and Gulf waters, and said coastal flooding is a concern for high tide cycles through mid-week. Laredo's forecast for the weekend carried rain chances of 60 to 100 percent, and the National Weather Service forecast just south of downtown San Antonio put the chance of precipitation at 90 percent on Sunday, with showers and a possible thunderstorm.
Source: National Weather Service Corpus Christi, Area Forecast Discussion, 12:24 a.m. CST, Nov. 7, 2026
What happens next
The Flood Watch runs until Monday morning. A watch means flooding is possible; if training storms set up over a city or a creek basin, the Weather Service can upgrade parts of the region to flash flood warnings, which mean flooding is imminent or already happening and require immediate action. The Weather Prediction Center will update its excessive rainfall outlook through the weekend, and rain is expected to taper early next week after lingering into Tuesday in parts of the Hill Country and the Gulf Coast. Residents in flood-prone areas — and the trucking companies that move freight through Laredo, the Valley and the Coastal Bend every day — should follow the Corpus Christi, Brownsville and Austin–San Antonio Weather Service offices for the latest statements before travelling on Sunday.