Catastropic Flooding in Texas Hill Country Second Year in a Row

It was "déjà vu all over again" when the skies opened up over the Texas Hill Country west and northwest of San Antonio this week. Daily rainfall totals from July 14 to July 17 in some locations exceeded 8 to 10 inches per day.

The same area experienced flash flooding last July 4th which resulted in at least 133 deaths. The two situations were similar in some respects, but there were significant differences. In 2025 heavy rainfall (8-10 inches) occurred in a relatively short amount of time (several hours) over a smaller localized area, resulting in extreme runoff and unprecedented rises in river levels, particularly the Gaudalupe River. It rose almost 29 feet in one hour causing massive devastation and loss of life.

The flooding this year occurred over a period of three days of heavy rain, and covered a larger area than in 2025. The long duration of the rain allowed for close monitoring and time to issue warnings and advisories.

The weather pattern that produced the environment favorable for heavy rain was a combination of a large upper level ridge of high pressure combined with low-level flow from the the Gulf into to Texas. The ridge extended north-south on an axis from the Big Bend are of Texas up the spine of the Rockies into Canada. High pressure over the Gulf of Mexico produced winds from the Gulf into Texas. The warm moist air was forced upward as it met a weak surface boundary across west-central Texas. Thunderstorm complexes developed along that boundary, tapping the continuous flow of moist air.  Thunderstorms developed repeatedly (training) over the same areas. Aloft, the steering currents at 19,000-20,000 feet were only 5 to 10 knots, meaning that thunderstorms would be moving very slowly if at all. 

Surface weather map July 16, 2026

500 millibar map July 16, 2026 showing area of very light winds at around 19,000 feet above central Texas

On July 14 (rain beginning on July 13) the highest rain totals were west of San Antonio along U.S 90. The heavy rain produced flash flooding, and many water rescues were reported. The highest CoCoRaHS observation was 8.63" at TX-MDN-64 near D'Hanis, TX. 

CoCoRaHS rainfall reports for July14, 2026

The Multi-Radar Multi-Sensor (MRMS) precipitation estimate shows a maximum of 12.17" (purple pixel in the white area).

24-hour radar estimated rainfall 8:00 a.m. July 14, 2026 

 

Rainfall amounts were even higher the next 24 hours, with the heaviest amounts northwest of the U.S. 90 corridor. The highest CoCoRaHS report was 12.09 inches at TX-RL-1 (Camp Wood 9.6 ESE), with radar estimates of more than 14 inches.. At this point two-day totals exceeded 14 inches (based on observations) and were very likely several inches higher.

CoCoRaHS observations the morning of July 15, 2026

Here is the MRMS 24-hour precipitation on July 15, with a core of 14+ inches of rain located about 12 miles southeast of Kickapoo Cavern State Park.

24-hour radar estimate rainfall 9:00 a.m. July 15, 2026

The highest rainfall totals occurred in the 24-hours ending on July 16, with an astounding 18.84 inches of rain at TX-KR-82 near Ingram, TX. A number of CoCoRaHS observers reported more than 10 inches of rain in Kerr County that morning. 

CoCoRaHS observation the morning of July 16, 2026

The MRMS estimate for the morning of July 16 showed two cores of heavy rain, one along U.S. 90 west of San Antonia and the other in Kerr County. The highest estimate the core in Kerr County was just a little over 13.62 inches, substantially less than actual observations from 15-18 inches. That's why actual observations - ground truth - are so critically important.

24-hour MRMS radar estimated rainfall for July 16, 2026 showing core of heavy rain over Kerr County, TX

When all was said and done, this rain event produced widespread severe flooding, significant property and road damage, and resulted in two fatalities. 72-hour estimated rainfall totals ending at 7:00 a.m. on July 16 over west central Texas revealed a huge area of 8+ inches of rain, with the highest amount estimated to be 27.63 inches in a core along U.S. 90 west of San Antonio. 

MRMS estimated rainfall fir the 72-hour period ending 7:00 a.m. July 16, 2026

Rain continued on July 16 and many locations received additional rain, but most amounts were less than an inch. Here are the top ten 96-hour amounts reported by Texas CoCoRaHS observers.

Over this period, there were 71 CoCoRaHS observers in west central Texas that reported 12 or more inches of rain, and 260 that reported 6 inches or more.

The NWS San Antonio office released a map showing the accumulation from Sunday through Thursday. Most of the rain fell July 13 through July 16 (observations July 14-July 17).

Here are the CoCoRaHS observations for that same period. 

Total accumulated rainfall July 12-17, 2026

Thanks to all of our observers who reported during the storms. No doubt many were dealing with their own localized impacts from the rain and flooding.  

 

A Recipe for Rain, Southwest Style

Much of Texas and the Southern Plains are currently in a worsening drought situation. The latest U.S. Drought Monitor released today shows D3 (Extreme) and D4 (Exceptional) drought from central Texas east northeast into southern Arkansas and the northern three-quarters of Louisiana.

Dryness has been slowly developing since the beginning of  summer, but the drying really accelerated in the past four to six weeks.

This map shows the change in drought status from September 22 to October 20, 2015

While Texas CoCoRaHS observers may not have been seeing much but dust in their rain gauges recently, that is about to change.  A "perfect" combination of circumstances will likely bring drought-busting rain to the region the next several days, but that has a down side as well.

The first weather feature in this recipe is an upper level trough with a closed low situated over the Four Corners. On the east side of this trough strong southwest winds are directing air into central Texas.

The 500 millibar map for 7:00 a.m. CDT October 22, 2015.

The second weather feature is Hurricane Patricia, which reached Category 4 strength this afternoon with sustained winds of 130 mph. Late this afternoon Patricia was located about 250 miles off the coast of Mexico moving northwest at 12 mph. The hurricane will turn north by tomorrow morning and likely make landfall on the Mexican coast late Friday afternoon or evening. Patricia will bring abundant moisture into Mexico, moisture that will be tapped by the trough over the southwest. Hurricane Patricia is the ninth Category 4 or 5 hurricane in the eastern Pacific this year, a new record. The latest updates on Patricia can be found at the National Hurricane Center web site.

Water vapor image of Hurricane Patricia at 1:45 p.m. PDT October 22. The eye of the storm is only 12 miles in diameter.

The third ingredient to this recipe for rain is moist flow off the Gulf of Mexico.

The 850 millibar map (~5000 feet) showing winds and relative humidity for 7:00 a.m. CDT Saturday, October 24.
Light green is RH of  =>70%, dark green is =>90%

All of this is expected to come together over Texas this weekend. The National Weather Service Office in San Antonio/Austin created a nice graphic showing how all of this is expected to come together.

This graphic shows the setup for the expected rain this weekend over Texas.

Rain is most welcome, but too much rain is not. The Quantitative Precipitation Forecast (QPF) for the three-day period ending Sunday evening at 7:00 CDT shows that much of the southeastern half of Texas will get several inches of rain, with a potential for as much as 13 inches between Austin and Dallas/Ft. Worth.

Quantitative Precipitation Forecast for the 72-hour period ending Sunday, October 26 at 7:00 p.m.

Of course this forecast may change based on how the weather features finally come together, but the primary message here is there will be lots of rain in a relatively short period, primarily from now through Saturday night. That means flooding. Just six months ago drought-ending rain occurred in Texas and Oklahoma, but it also resulted in major and in some cases record flooding on many rivers in Texas. This weekend's rain will not necessarily be a repeat of last May, providing there aren't successive heavy rain events in the next month or so. By early next week the focus of heavy rain will be southern Louisiana as the system moves east

A wide swath of central Texas and south-central Oklahoma is under a flash flood watch beginning Friday morning into Sunday. Be sure to visit your local National Weather Service web site for the latest information and updates.

Watches, warnings, and advisories in effect as of 5:08 p.m. CDT