Here is some information from the National Hurricane Center about Potential Tropical Cyclone One. 

...DISTURBANCE EXPECTED TO BRING HEAVY RAINS AND COASTAL FLOODING
TO PORTIONS OF TEXAS AND NORTHEASTERN MEXICO...
...FORECAST TO BECOME A TROPICAL STORM BY WEDNESDAY...

SUMMARY OF 1000 AM CDT...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...21.8N 92.7W
ABOUT 355 MI...570 KM ESE OF LA PESCA MEXICO
ABOUT 410 MI...660 KM SE OF BROWNSVILLE TEXAS
MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H
PRESENT MOVEMENT...N OR 5 DEGREES AT 7 MPH...11 KM/H
MINIMUM CENTRAL PRESSURE...999 MB...29.50 INCHES

Some areas will see storm surge, even normally dry areas. Five to ten inches of rain are expected and some areas could see as much as 15 inches. Some areas will see storm surge. Tropical storm force winds are expected within the warning area by tonight or wednesday. A couple tornadoes could occur across parts of deep south Texas on Wednesday.