A weak upper level low moved into Texas from the Gulf of Mexico and interacted with a very moist environment. Precipitable water values across South Central Texas were above two inches. When a low level jet developed overnight, this combination was sufficient to produce heavy rain that led to flash flooding. There were rainfall reports of 10.18 and 9.25 inches in the extreme northern part of San Antonio.

Flash Flood in BEXAR, TEXAS
From 03-SEP-18 20:52:00 to 03-SEP-18 22:45:00 (CST-6)
Location: HOLLYWOOD PARK
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Thunderstorms produced heavy rain that led to flash flooding. There were high water rescues and evacuations on Glass Canyon along Mud Creek just north of San Antonio.

Flash Flood in BEXAR, TEXAS
From 03-SEP-18 21:55:00 to 04-SEP-18 00:00:00 (CST-6)
Location: ROBARDS
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Thunderstorms produced heavy rain that led to flash flooding. Cars were stranded in high water at I410 and NW Military Dr. in northern San Antonio. There were also dozens of other roads closed across the city.

Flash Flood in BEXAR, TEXAS
From 03-SEP-18 22:20:00 to 04-SEP-18 00:00:00 (CST-6)
Location: SAT TWIN OAKS ARPT
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Thunderstorms produced an estimated eight inches of rain that caused flash flooding. Water covered the road at Bitters Rd. and Hwy 281 in northern San Antonio.

Flash Flood in BEXAR, TEXAS
From 04-SEP-18 00:00:00 to 04-SEP-18 01:45:00 (CST-6)
Location: SAT TWIN OAKS ARPT
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Thunderstorms produced heavy rain that led to flash flooding sending two feet of water over a low water crossing on Cibolo Creek in Bulverde.

Flash Flood in BEXAR, TEXAS
From 04-SEP-18 01:00:00 to 04-SEP-18 02:00:00 (CST-6)
Location: (SAT)SAN ANTONIO INT
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Thunderstorms produced heavy rain that led to flash flooding. Multiple roads and low water crossing were flooded across north central San Antonio between I-410 and Loop 1604.

Flash Flood in UVALDE, TEXAS
From 04-SEP-18 02:00:00 to 04-SEP-18 05:45:00 (CST-6)
Location: SABINAL
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Thunderstorms produced heavy rain that led to flash flooding. Several roads around Sabinal were closed due to flooding along the Sabinal River including RM 187 and TX 127.

Flash Flood in BEXAR, TEXAS
From 04-SEP-18 03:30:00 to 04-SEP-18 05:00:00 (CST-6)
Location: ROBARDS
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Thunderstorms produced heavy rain that led to flash flooding closing multiple roads in north central San Antonio.

Flash Flood in BEXAR, TEXAS
From 04-SEP-18 06:30:00 to 04-SEP-18 09:00:00 (CST-6)
Location: SAT TWIN OAKS ARPT
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

Thunderstorms produced eight to 10 inches of rain across the northern part of San Antonio that led to flash flooding. The San Antonio Fire Department reported 63 high water rescues across the city. Multiple roads and low water crossings and several area creeks were flooded.