A weak disturbance in the Gulf of Mexico will bring beneficial rain to parts of the Rio Grande Valley.
An extensive low pressure trough is currently in the northwestern Gulf, and will continue to move west in the next 24 hours.
As it does so, it will move a deep layer of moisture into deep South Texas.
The moisture will combine with lift from the system to trigger numerous showers and thunderstorms.
The chances will move west in conjunction with the general motion of the low.
The Lower and Mid Valley could see activity pick up tomorrow morning, spreading to the Upper Valley through the afternoon.
A 60-70 % chance exists Thursday, dropping slightly to 50-60 % Friday, before becoming scattered rain Saturday at 30%.
Motorists be advised that heavy pockets of rain could reduce visibilities and create ponding on roadways.
Some isolated pockets could see 2-4 inches over the 72-hour span.