San Antonio flash flood warning: crossings closed, more rain forecast

San Antonio remained under a flash flood warning on Thursday, October 1, after emergency managers reported flooding and numerous closed low-water crossings across the warned area. The National Weather Service’s 3:23 p.m. CDT statement kept the warning in effect until 7 p.m., with more rain possible overnight.

Between 1 and 4 inches of rain had already fallen across the warned area, according to the NWS. Its statement classified flash flooding as observed and the damage threat as “considerable,” warning of life-threatening flooding affecting creeks, streets, highways and underpasses.

The change since NewsJaws’s earlier flood-watch coverage is concrete: Thursday’s official statement documents flooding and crossing closures. The immediate warning covers Bexar County, northern Atascosa County and western Wilson County; it is not a statewide alert.

Which areas does the San Antonio warning cover?

The NWS warning lists San Antonio, Schertz, Converse, Pleasanton, Floresville and Helotes among threatened communities. San Antonio International Airport also appears in the list. That identifies locations exposed to the flood threat; it does not establish an airport closure or flight disruption.

Rainfall rates had decreased during the hour before the 3:23 p.m. statement, yet up to another inch remained possible within the warned area. Those figures describe that warning’s area and period, rather than a reading from one San Antonio rain gauge.

Why the warning and watch have different deadlines

The flash flood warning was scheduled to end at 7 p.m. CDT Thursday, October 1. A broader flood watch runs through 7 p.m. CDT Friday, October 2. The watch includes the I-35 corridor and portions of the Hill Country, Coastal Plains and Rio Grande Plains.

The two alerts describe different levels of certainty. In the NWS explanation of flood alerts, a watch means conditions favor flooding, but flooding is not certain. A flash flood warning means flooding is imminent or occurring. In this case, the warning specifically records observed flooding.

Thursday’s warning deadline therefore does not mark the end of the wider forecast threat. Nor does a scheduled expiry establish that water will have receded. The statement is a flash flood warning with a considerable damage threat, not a declared flash flood emergency.

How much more rain is forecast through Friday?

The NWS regional forecast attributes the continuing threat to a cold front interacting with tropical moisture. It forecasts another 1–4 inches through Friday across the eastern two-thirds of South Central Texas, with isolated pockets of 6–8 inches. Storm redevelopment may persist across central and eastern areas into Friday morning.

These are additional rainfall forecasts over a broad region, not measured totals for San Antonio. They should not be added to the warning’s observed rainfall figures to produce a city total: the areas and time periods differ.

MySA reported that the severe-storm risk had decreased, with an isolated strong-storm threat involving gusts of 30–40 mph. But its report retained the potentially life-threatening flood threat. A lower severe-storm risk did not mean the flooding risk had ended.

What the Texas forecast means for Houston

In their Thursday morning report, KPRC chief meteorologist Anthony Yanez and meteorologist Justin Stapleton forecast 2–4 inches of rain, locally 5–8 inches, for the regional flood threat. They cautioned that “there will be a wide range of rain totals.” Those projections are not observations or promises of identical rainfall in every city.

KPRC said Southeast Texas was outside the flood watch at the time of that morning report. Its meteorologists expected isolated Houston thunderstorms Thursday afternoon, followed by more widespread rain Friday afternoon and rain chances through the weekend. That is a separate forecast timeline from San Antonio’s already documented flooding.

What residents should monitor next

The NWS warning gives a direct instruction: “Be aware of your surroundings and do not drive on flooded roads.” Its flood guidance says flash floods can develop within minutes to hours, including in places where rain is not immediately falling, and advises people in flood-prone areas to move immediately to high ground when warned.

The next developments to watch are any extension, replacement or cancellation of the official warning, alongside updates on overnight storms and Friday rainfall. The 3:23 p.m. continuation statement establishes the conditions reported Thursday afternoon; its scheduled deadline should not be treated as an all-clear for individual roads.