A Flash Flood Watch has been issued for the entire Rio Grande that will take effect from 7 p.m. Thursday through Saturday morning.

The National Weather Service in Brownsville reports an upper level trough of low pressure across west Texas will continue to bring abundant moisture across portions of Deep South Texas tonight into Friday, while at the same time a frontal boundary remains stationary across South Texas.

The NWS reports this will provide the potential for heavy rainfall across the Valley tonight through early Saturday morning. There’s a 40% chance of thunderstorms tonight and a 60% chance of thunderstorms on Friday. There’s a 50% chance of thunderstorms on Friday night and a 40% chance for thunderstorms on Saturday.

Forecasters say rainfall from the past week has provided saturated soils across most portions of Deep South Texas. Rainfall amounts of 1 to 3 inches can be expected tonight through Friday night with isolated amounts up to 5 inches.

The NWS says low-lying and poorly-draining areas will experience flash flooding. Heavy rainfall over a short period of time will cause difficulty in driving. Motorists are urged to find alternative routes if flooding roadways are encountered.