The National Weather Service in Brownsville has issued a flash flood watch for most of the Rio Grande Valley through 7 a .m. Wednesday.
A flash flood watch means that conditions may develop that lead to flash flooding.
The affected areas included Coastal Cameron, Coastal Willacy, Inland Cameron, Inland Willacy, Northern and Southern Hidalgo counties.
The NWS reports a moist and unstable atmosphere is still in place over Deep South Texas and as daytime heating occurs along with a possible sea breeze boundary, scattered to numerous storms and thunderstorms could develop, especially east of Highway 281/I69C.
Additional rainfall amounts of 1 to 3 inches are possible and could cause additional flooding to areas that saw heavy rain last night, the NWS states.
Slow moving heavy showers and thunderstorms dumped up to 10 to 12 inches of rain in western Cameron, western Willacy and eastern Hidalgo counties Monday night. More rain could cause renewed flashing flooding.
The NWS reports flooding of roads, streets, and low-lying agricultural areas with water depth up to 5 feet may occur. Heavy rainfall in a short period of time will cause street and creeks to overflow.
Driving could be difficult to impossible and motorists are urged to find alternative routes.
There’s a 50 percent chance of heavy rain today in Brownsville, a 40 percent to 70 percent chance of heavy rain in Harlingen, and a 50 percent chance of heavy rain in McAllen.