FROM THE NATIONAL WEATHER SERVICE:
Flash Flood Watch extended through 7 PM today
Heavy rain threat today will be mainly west of Highway 281 (from San Antonio west to the Rio Grande)Threat for locally heavy rain and flash flooding will shift west through the day. Flash Flood Watch may be cancelled early.
Key Messaging Points:
Not everyone in the watch area will see rain today. Those that do may experience isolated flash flooding issues.Additional rainfall amounts of 1-2 inches with isolated event totals near 4 inches are possible through the day today. Highest flash flood risk west of Highway 281 and south of I-10 through Sunday evening.Heavier rain will occur within rain bands, but difficult to pinpoint where bands will develop.Flash flooding of low water crossings, underpasses, and urban areas possibleMinor to moderate flooding expected on Rio Grande, Nueces, Frio, and San Antonio Rivers.
Area of Concern:
Coastal Plains, San Antonio metro area, portions of the Hill Country, and Rio Grande Plains
Threats & Impacts:
Rainfall: Widespread 1-2" with locally higher amounts near 4" event totals in the Flash Flood Watch area. Several locations may experience minor flooding with flood waters capable of causing small streams, creeks, canals, and ditches to become swollen and overflow in a few places, but with little to no property damage. Quick ponding of water occurs at underpasses, low-lying spots, and poor drainage areas. Storm drains and retention ponds become near-full and begin to overflow in a few places. Flood waters may prompt brief road closures.
A disturbance is located near Eagle Pass early this morning. Bands of showers and isolated thunderstorms associated with this disturbance will continue to bring heavy rain as they move into the region from the south and southeast today. It is still difficult to pinpoint with any certainty where these bands will set up, but the highest flash flood risk through this evening appears to be south of I-10 and west of I-37. Widespread 1-2" rainfall amounts with locally higher storm event totals near 4" will be possible in the Flash Flood Watch area. The latest computer models indicate the potential for rain bands to develop may persist through the day today, which is why the Flash Flood Watch was extended. It is important to keep in mind that not everyone in the watch area will see rain today, but those that do may experience isolated flash flooding from heavy rainfall. As the disturbance moves farther west today into northern Mexico, the heavy rain and flash flood threat will also shift west and exit the region by this evening. Should the flash flood threat end sooner than anticipated, the Flash Flood Watch may be cancelled early.